City went into the match with a commanding 6-0 lead from the first leg and extended that almost immediately as Alvaro Negredo nodded home from close range in the third minute.
Sergio Aguero doubled his side's lead on the night 20 minutes later, while Negredo got his second of the evening and fifth of the tie just before the hour mark to seal the victory.
You can read how the full 90 minutes unfolded with Sports Mole's live coverage of the match below.
6.45pmGood evening! Thank you very much for joining Sports Mole for tonight's Capital One Cup semi-final second leg between West Ham United and Manchester City! In truth, the outcome of the tie is already all but decided, but the form City are in it is always a joy to watch them, while the hosts will have pride to play for, so we should still have a good game on our hands!
6.47pmWe'll start by looking at our hosts tonight, and manager Sam Allardyce will be think that the only way is up following his last meeting with Man City. The 6-0 defeat in the first leg compounded a miserable week for the Hammers having also been beaten 5-0 by Nottingham Forest before that and, while things have improved slightly since then, they are still deep in the mire and Allardyce's job looks to be increasingly unsafe.
6.49pmWest Ham have won just once in their last eight outings in all competitions, losing six of those games. Their struggles during that time can perhaps best be represented by the goals for and against. They found the net just seven times in the eight outings, while conceding 25.
6.51pmThat run has left them in the bottom three of the Premier League, one point from safety. It is very tight in the bottom half of the table at the moment, so Allardyce knows that a couple of wins could make things look a lot better for his side, but such wins have not been easy to come by recently.
6.53pmIt has - for the most part - been a different story in the League Cup this season. The Hammers have beaten Cheltenham, Cardiff, Burnley and Tottenham on their way to the semi-final, scoring nine goals and conceding four in those four matches. However, their good form in the competition came to an abrupt end in the first leg of this tie, and they find themselves playing this match as little more than a high-profile friendly now.
6.55pmHome advantage is likely to help the Hammers today - if only because it prevents City from being at the Etihad, where they have been rampant this season. The hosts have not been great at Upton Park recently, however, with just one win in their last eight matches in front of their own fans. Even more worryingly, they have started to ship a lot of goals at home, conceding three in each of their last three games.
6.57pmWest Ham's 6-0 defeat in the first leg equalled an unwanted record that they themselves already held. The Hammers have been on the end of the two biggest ever defeats in League Cup semi-final history, both by the 6-0 scoreline. In addition to the City defeat, they were also thrashed by Oldham back in 1990.
6.59pmThey have also lost five of their last six League Cup semi-final outings, last reaching the final in 1981. That was one of two visits to Wembley as League Cup finalists for West Ham, although they have never won the trophy, losing in both 1981 and 1966. However, they do usually score at home in the League Cup, having found the net 34 times in their last 35 games.
7.01pmAnother side who certainly don't have trouble scoring is City. They smashed through the 100-goal barrier during Saturday's 4-2 win over Cardiff, taking just 34 games to reach the milestone. They have been unstoppable at home this season but, worryingly for everyone - and especially West Ham - have been increasingly impressive away from home recently.
7.03pmThey come into this match on the back of a tremendous 17-game unbeaten streak in all competitions, and it is hard to see who is going to stop them in the immediate future. They have won 15 of those 17 games, including victories over the likes of Bayern Munich, Arsenal and Liverpool.
7.05pmThe Blues now sit second in the Premier League table, one point leaders Arsenal and having scored more goals than any other side in the division, with 63. In addition to the Premier League crown, City are still harbouring realistic ambitions of claiming an unprecedented quadruple and, with their passage into the final of this competition now a formality, they can rest players ahead of what will be a packed fixture schedule for the rest of the season.
7.07pmThat, couple with their away form this season, may give West Ham a glimmer of hope in tonight's match, but Pellegrini will still be confident that his side can win yet again. They may have been beaten by Cardiff, Aston Villa and Sunderland on their travels already this season, but City are now unbeaten in their last eight away games. However, in the midst of that run, they did draw to Championship side Blackburn.
7.09pmCity's route to the semi-final has seen them thrash Wigan 5-0, edge past Newcastle 2-0 after extra time, and beat Leicester 3-1 in the quarters. In addition to their 6-0 win in the first leg of this tie, that puts their statistics at an impressive 16 goals scored and just one conceded in this year's League Cup.
7.11pmCity have won this competition twice before, lifting the trophy in 1970 and 1976. Barring the most miraculous comeback from West Ham, they will reach the final again this season, where they will meet either local rivals Man United or Sunderland on March 2. Whatever the result in tomorrow's semi-final, Pellegrini will be confident of picking up his first trophy as City manager on that day.
7.13pmCity are unbeaten against West Ham in their last eight meetings in all competitions, while they also have a good record against the Hammers in the League Cup. Before this season's tie, the two teams had met just twice in this competition, with City winning a replay 2-1 at Upton Park following a 0-0 draw at Maine Road.
7.15pmTEAM NEWS: Right, time for some team news I think! There are notable inclusions for both sides, with West Ham naming Andy Carroll up front as he continues his recovery from a lengthy injury. There are also places for Kevin Nolan and James Tomkins, who return from suspension. City, meanwhile, have made a number of changes as expected but still field the fearsome front two of Negredo and Aguero. Full team news for both sides on the way...
7.17pmWEST HAM STARTING XI: Jaaskelainen; Tomkins, Rat, Johnson, Taylor; Nolan, Morrison, Diarra, Diame, J. Cole; Carroll
7.17pmWEST HAM SUBS: Jarvis, Collison, Adrian, Noble, Downing, C. Cole, Chambers
7.19pmMAN CITY SUBS: Hart, Demichelis, Rodwell, Dzeko, Zabaleta, Jovetic, Kolarov
7.21pmSo, what can we make of those two sides? Well, there aren't any major surprises in either, but it is a bit unexpected to see Carroll play from the start for the Hammers. He is still working his way back to full fitness after that toe injury, so he is unlikely to play the full 90 minutes. However, he was always expected to be involved in this one one way or the other, with Allardyce marking this match down as a chance to get players back towards 100%.
7.23pmIn truth, Allardyce's hands were tied with his selection in some respects. He doesn't have enough defenders to rotate like City do and was forced to name a completely unfamiliar back four in their Premier League game at the weekend. The return of Tomkins is a boost for him, however, as it gives him one more option at least.
7.25pmIn midfield, Nolan returns as expected having served a four-game ban. He has a tremendous record when playing with Andy Carroll, so those two could be key to any hopes West Ham have of pulling off a shock on the night. It is also interesting to see Ravel Morrison included despite continued speculation over his future, and indeed his happiness at the club. At his best, he can be a real handful, but his head may be elsewhere tonight.
7.27pmAs for City, Pellegrini has taken the opportunity to name a number of fringe players in the team, as we expected he would. Still, it is a strong lineup for the visitors and certainly one capable of winning the game.
7.29pmCostel Pantilimon has already shown that he is an able deputy for Hart this season, so there will be no worries in that regard tonight. In front of him, Lescott and Clichy both have bags of experience and would make it into most Premier League first teams, while Nastasic has also see his fair share of action already this season. The one question mark may be over Boyata, but the youngster will view this game as a real chance to show what he can do.
7.31pmCity's 'weakened' midfield still includes the likes of Jesus Navas, who has impressed since joining the club in the summer. His speed is enough to cause anyone problems and, when you have strikers like he has in the box, it makes his job of setting up chances a whole lot easier. Fernandinho has also shown that he has an eye for goal, so West Ham will be well advised to watch his runs from deep tonight.
7.33pmUp front, City call in the big boys as Negredo and Aguero start together once again. Both players have 21 goals each to their name already this season, which is one fewer than the entire West Ham squad have managed in the Premier League. Aguero is easing himself back to fitness but made an immediate impact on his recent return, while Negredo has scored six goals in four games during the Argentine's absence.
7.35pmPREDICTION: They say that nothing is impossible in sport, but we may have just found something that is. Sorry to say it West Ham fans, but there is no chance that the Hammers will qualify for the final of this competition. On the night, however, I expect things to be a lot closer than they were in the first leg. City's form and depth is such that I still can't look past them for the win, but West Ham should put up a good fight. I'll go for 3-1 to the visitors.
7.37pmIt is interesting to see Dzeko left on the bench for City today. He would usually be the type of player that would start these games, but perhaps the fact that he is left out is a sign that he will be important to Pellegrini for the rest of the season. He has certainly scored plenty of goal during Aguero's absence, so will he see more first team action in the coming weeks?
7.39pmOne thing that will be intriguing about this game is what approach Allardyce takes to it. The match is, essentially, a dead rubber, so he will surely be more worried about his side's plight at the bottom of the Premier League right now. However, another thrashing could be very damaging to morale, while a surprise victory could have the opposite impact.
7.41pmA reminder that the winner of this tie (ie Man City) will face either Sunderland or Manchester United in the League Cup final at Wembley on March 2.
7.43pmCity became centurions on the goal front at the weekend, and no less than nine of them came against West Ham. That tally is likely to increase further tonight, while they will also meet once again in the Premier League later in the season.
1 minKICKOFF: City get us underway at Upton Park. Can they add to their huge aggregate lead or will West Ham pull off a shock victory on the night?
3 minGOAL! West Ham (0)0-1(7) Man City (Alvaro Negredo)
3 minOh my word, what a horror start that is for West Ham. Negredo, who scored a hat-trick in the first leg, gets City up and running and it could not be easier for the Spaniard. He was left completely unmarked inside the box and had the simplest task to just nod the ball past Jaaskelainen. That is woeful defending from the hosts.
5 minWest Ham have had their fair share of bad luck in defence this season, but that was all their own doing. There were two Claret and Blue shirts in the box, but neither took it upon themselves to pick up Negredo, who was in yards of space.
6 minDISALLOWED GOAL! The sparse crowd at Upton Park think that they have seen an equaliser, but their celebration are soon cut short by the linesman's flag. Taylor swung a decent ball into the box for Nolan to slam home, but the Hammers skipper was just a yard offside when the cross came in.
8 minAguero lines up Johnson on the left side of the box and drops a shoulder to beat him far too easily. He tries to catch out the keeper with a fierce shot towards the front post, but his effort was a few yards wide with plenty of teammates waiting in the middle.
10 minWest Ham have actually responded quite well to going behind, making some decent progress into the City half. However, you get the feeling that the visitors are barely out of second gear, and they still look dangerous when they go forward.
11 minCarroll causes problems in the air for the City defence and the ball skims off the head of Nastasic, dropping to Diame. The midfielder takes a touch but then lashes his shot well wide of the near post.
13 minYou can see that Carroll has made a difference to West Ham's play already. Midfielders know that they can gamble past the shoulder of their striker due to the likelihood of him winning a header and flicking the ball on for them. It isn't exactly total football, but it could prove effective for the Hammers in their relegation battle.
15 minCHANCE! Diame does well down the right wing, battling away to work space for a cross. He hangs the ball into the area and, while the City defenders wait for it to come to them, Carroll attacks it and gets there first, only to miscue his header and send it over the bar. Perhaps with a few more games under his belt he would have buried that.
16 minSAVE! Taylor gets caught in possession on the halfway line and Aguero immediately drives at the West Ham defence. No-one comes to meet him so he guides a shot towards the bottom corner from 20 yards that draws a good stop from Jaaskelainen.
18 minDiame is looking positive today. Once again when gets the ball his first thought is to attack, and this time he draws a save from Pantilimon. He throws in a couple of stepovers for good measure before driving a low effort towards goal from the edge of the box, but it is easy for the City keeper.
20 minIt is interesting to see how City's gameplan will pan out this evening. They are cruising at the moment and I doubt that they will get anywhere near their best today, but a number of fringe players are getting a chance so they will be keen to show what they can do.
22 minThe home fans are giving their side the 'Ole!' treatment for every successful pass they make now. It's good to see that they can find something to cheer for in this current situation - not many fans would at 7-0 down on aggregate.
24 minGOAL! West Ham (0)0-2(8) Man City (Sergio Aguero)
24 minCity double their lead, and it is the other half of their deadly strike partnership that gets the goal this time. Lopes deserves a lot of credit for creating the chance, beating a number of tackles before chipping the ball through to Aguero. Two West Ham defenders are in close attendance but they fall over each other, allowing Aguero a clear chance to send a small dink over the diving keeper.
26 minThat goal makes it 8-0 on aggregate and the way things are panning out here I wouldn't bet against that reaching double figures tonight. City are playing the game at their own pace and looking capable of scoring whenever they choose.
28 minNegredo gets a lucky bounce off a defender while trying to play a pass to Navas, with the ball bouncing invitingly into space on the edge of the area for the Spanish striker. He drills a powerful low effort towards goal, but it is straight at Jaaskelainen, who makes the save.
30 minCity are controlling the ball at the moment as West Ham continue to chase shadows. The hosts have looked decent at times going forward tonight, but it is clear that they are just not in the same clash as their opponents.
32 minYELLOW CARD! Aguero is the first man in the book for a couple of tackle that he jumped into without leaving his feet. They were strange challenges from Aguero and they could have been dangerous had he connected with either Nolan or Tomkins.
34 minThis is turning into a bit of a training exercise at the moment. West Ham are getting well versed in their defensive formation while City are knocking the ball about patiently looking for an opening.
36 minWorrying sign for City as Aguero goes down clutching his leg after an off-the-ball collision on the left side of the box. He should be able to continue, but that is a reminder for Pellegrini that injuries are perhaps his most dangerous opponent in this tie now.
38 minYELLOW CARD! Really good play from Lopes as he battles away against Diarra to win the ball back in midfield, prompting the West Ham midfielder to bring him down with a cynical tackle that earns him a yellow.
40 minCredit to the West Ham fans, they haven't stopped singing so far. There are a lot of empty seats at Upton Park this evening but those who did come seem determined to have a good time. I doubt they would have been expecting a win anyway.
42 minUPDATE: There is also an FA Cup match taking place tonight, and at the moment Charlton are leading Oxford in that match. The Addicks are 2-0 up and look set for the fourth round.
44 minCarroll seems to have had an effect on the City defence one way or another. Lescott just had a free header to clear the ball, but instead he tentatively put it behind for a corner before looking round like he was expecting to be clattered by the former Liverpool man.
45 minThere will be just the one minute of added time at the end of this half.
45+1 minSpeaking of Carroll and clattering, he does exactly that to Pantilimon, leaving the keeper in a heap after challenging him for an aerial ball. The Romanian held on to the ball, but he may choose to punch it next time.
45+1 minHALF TIME: West Ham United 0-2 Manchester City
8.40pmWell, that was all very easy for City. They have added further to their already comprehensive aggregate lead and are now 8-0 ahead over the two legs. West Ham's mission to save face and play for pride looks destined for failure after a first half where they couldn't match a second-string City team playing nowhere near their best.
8.42pmThe opening goal came after just three minutes and it is not one that Sam Allardyce will want to see again. There was a complete lack of communication between Tomkins and Rat, leaving Negredo in yards of space inside the box to nod a simple finish past the keeper. The second goal also left a lot to be desired from a defensive point of view as Lopes beat a number of tackles to feed Aguero, who held off a further two challenges before beating Jaaskelainen with ease.
8.44pmIn truth, City look capable of scoring whenever they come forward, and they still haven't moved above second gear tonight. It has been as easy as you like for them, and the only thing that could harm the visitors in this match seems to be injuries. I would be surprised if the likes of Aguero and Negredo lasted the full 90 minutes, especially with a player like Dzeko waiting on the bench.
8.46pmAllardyce would not have gone into this game expecting a miraculous comeback, so he won't be too surprised with how things have gone so far. He will, of course, be disappointed at the defending that lead to the goals, but there have been positives for him to take. His side responded well to going behind early on and, while they haven't forced Pantilimon into any really tough saves, they were quite positive in the first 25 minutes or so.
8.48pmPerhaps the biggest plus that Allardyce can take from the match is the performance of Andy Carroll. The big striker is easing his way back to full fitness but today's match has been a good runout for him. He may not last too much longer, but he has been a handful at times.
8.49pmWEST HAM SUB: Indeed, Carroll will not last any longer as he makes way at half time to be replaced by Carlton Cole.
46 minKICKOFF: West Ham get us back underway at Upton Park for the second half of this League Cup semi-final second leg. Can they at least get a goal on the board or will it be another win to nil for City?
48 minWEST HAM SUB: This is a strange sub, happening just two minutes after the restart. Stewart Downing replaces Joe Cole, who immediately runs down the tunnel, suggesting that he may have picked up a slight knock.
49 minQuick feet from Morrison in the box as he pounces on a loose ball before trying to beat Lescott in a tight area. Lescott sticks a leg out and Morrison goes tumbling over it, but the referee waves away the claims for a penalty, and rightly so.
51 minCHANCE! One long way upfield sees Carlton Cole peel away from the defence and move into the area. He has two men to beat but shows good feet to skip away from Nastasic before seeing his shot saved by Pantilimon. That was good play from the striker, and it was West Ham's best chance of the match so far.
53 minCity pour forward with a fluid break and Fernandinho gives the ball out wide to Navas. The winger has all the time in the world to decide what he wants to do with it, but his eventual cross is poor and easy for Jaaskelainen to claim.
54 minWest Ham have a free kick in a good area here as Nastasic fouled Cole after completely missing an attempted clearance. Can they make anything of it?
55 minNo. Morrison lines it up and slams it right into the middle of the wall. That was a poor effort from the youngster.
57 minDowning plays a long ball to the back post which Cole leaves for Diame, steaming in from the right flank. He chooses not to hit it first time, somehow resisting the urge, instead controlling it and working his way backwards to find space to shoot. Cole is in his way the whole time, however, and the striker eventually inadvertently tackles his own man.
59 minGOAL! West Ham (0)0-3(9) Man City (Alvaro Negredo)
59 minSuperb from Negredo. He collects Aguero's short pass 25 yards from goal and drives into the area, showing good pace and power to beat a sliding tackle while holding off another challenge. Jaaskelainen looks to have the situation under control when he comes out to narrow the angle, but Negredo slides and delays his shot before dinking it over the keeper. Super finish from 'The Beast'.
61 minGreat play from Morrison as he shows quick feet to dance into the box and create a shooting opportunity. He does everything right in the build up, beating three or four defenders, but Lescott dives in the way of his shot to make a good block.
63 minWorrying signs for the Hammers as Diame goes down with an injury. He picked it up while nicking the ball off Negredo, and it looks like he may have twisted his knee. The last thing West Ham need now is more injuries.
63 minMAN CITY SUB: Rodwell is slowly coming back to fitness and he will get just under half an hour here as he replaces Javi Garcia.
64 minYELLOW CARD! Clichy goes into the book for a robust challenge on Morrison, who was threatening to race away and launch a quick break for his side.
65 minMAN CITY SUB: Pellegrini gives another player who has struggled with injury a chance as Stevan Jovetic comes on in place of Sergio Aguero.
67 minMorrison is starting is get more and more involved in the game, which can only be a good thing for the hosts. Everything they do is beginning to run through him, which is in contrast to the first half when it often bypassed him as the ball was played high towards Carroll.
69 minThere are just over 20 minutes remaining in this match and the only real questions seem to be whether City will reach double figures on aggregate and whether Negredo will get another hat-trick against the Hammers.
71 minOFF THE POST! City play a free kick routine that they spend a while planning, passing the ball short before giving it back to Lopes, who made his way down the right. The youngster then slices his cross but almost gets a lucky break as it nearly sneaks in at the near post, hitting the outside of the upright.
72 minPatient play from City as they make a couple of breaks behind the West Ham defence before being forced to cut back. Navas crabs his way across a crowded area before teeing up Fernandinho who takes a touch before blasting a shot high and wide from 25 yards.
74 minCLOSE! West Ham come very close to getting a consolation goal! A corner is swung into the box and Carlton Cole rises highest to meeting it, beating Rodwell in the air to send a header narrowly past the post.
76 minCHANCE! Big chance for Navas to make it 4-0 to the visitors. City win the ball back in midfield and Negredo does well to draw three defenders towards him before slipping the ball to Navas. The winger has time to compose himself just inside the box, but proceeds to send his effort high over the bar. He should have done better there.
78 minMAN CITY SUB: The visitors' final change of the night sees Kolarov replace Navas, which means that Negredo will see out the 90 minutes. Can 'The Beast' get his hat-trick?
80 minPellegrini only named one untried youngster in his side for this match, and Lopes will have pleased the City manager tonight. He has been positive and made some telling contributions to the game, which will not have done his future chances any harm at all.
82 minDowning plays a ball back to the edge of the box but Diame's volley is badly sliced. The ball falls into the path of Cole, however, and he holds off his marker before shooting from close range on the turn, only to see his effort well blocked.
84 minThis is not something that Pellegrini will want to see. Negredo goes down heavily under a challenge from Tomkins and lands on his shoulder, immediately calling for attention while writhing in agony on the floor. Negredo is not one to make a meal of things and, with City having already made all three subs, the visitors could be forced to see out this game with 10 men.
86 minAfter receiving some treatment off the pitch Negredo is finally back on now, but he is still holding that shoulder of his. He might want to take things easy in the closing four minutes of this match.
88 minNow there is a lengthy stoppage for an injury to Diame. The challenge that caused the problem seemed fairly innocuous, it must be said, but he will leave the pitch on a stretcher. That is a huge blow for West Ham, who are already struggling with injuries.
90 minWEST HAM SUB: Diame is carried off the field in obvious pain, and he will be replaced by Jack Collison for the closing stages of this match.
90 minThere will be one minute of added time at the end of this match.
90+1 minFULL TIME: West Ham United 0-3 Manchester City (Manchester City win 9-0 on aggregate)
9.37pmCity complete the formalities with a 3-0 victory in the second leg, sending them through to the League Cup final on March 2. Coupled with their comprehensive win in the first leg it was a 9-0 aggregate win for Manuel Pellegrini's side, and you can't even say that such a scoreline flatters them.
9.39pmThe goals in tonight's game from the ever-reliable sources of Alvaro Negredo and Sergio Aguero. Negredo broke the deadlock after just three minutes with a simple header from close range having been left completely unmarked in the area. Aguero then doubled the lead on the night with a neat finish after escaping the attentions of two West Ham defenders, while Negredo made it five goals for the tie with a bullish run and delicate chip in the second half.
9.41pmWest Ham's aims going into this match would have been to avoid any further humiliation and restore a bit of pride following the 6-0 defeat in the first leg, and it was certainly a much-improved performance from the hosts. However, the gulf in class between the two sides was evident throughout and the hosts never really looked like scoring.
9.43pmAs for City, reaching the final was all but guaranteed for them before the match, and as such they rarely had to raise the tempo this evening. They played at their own pace for much of the game and controlled proceedings from start to finish. It says a lot they they didn't have to be at their best yet still cruised to a 3-0 win. That puts them in the final, where they will face either Manchester United or Sunderland.
9.45pmRight, that is all we have time for tonight! Thank you very much for joining Sports Mole for tonight's League Cup semi-final as City produced another three goals to cruise into the final with a 9-0 aggregate victory. I will leave you with our match report, and be sure to stick around for reaction and analysis, which will be on the site soon. We have coverage of the second semi-final for you tomorrow as Man United look to overturn a deficit against Sunderland for the chance to meet City in the final. From me, though, it is goodbye for now!