The visitors took the lead in spectacular fashion on eight minutes when Wayne Rooney lobbed West Ham goalkeeper Adrian from just inside the opposition half.
Rooney then doubled United's advantage with 33 minutes played as he converted from close range following some poor defending from the hosts.
Read Sports Mole's minute-by-minute report below to find out how all of the action unfolded at Upton Park.
4.30pmHello there and welcome to Sports Mole's live text coverage of this evening's Premier League encounter as West Ham United welcome Manchester United to Upton Park. We should have the team news coming through shortly.
4.34pmUPDATE: There are currently six other matches being played in the Premier League, nearly all of which have seen plenty of goals. We'll bring you those results as soon as they're through. Meanwhile, today's early kickoff saw Chelsea dismantle Arsenal 6-0 at Stamford Bridge. You can read all about that one right here.
4.36pmWEST HAM SUBS: Reid, Jarvis, Armero, Jaaskelainen, C Cole, J Cole, Nocerino
4.39pmWest Ham boss Sam Allardyce makes two changes to his side following last weekend's 3-1 defeat at Stoke City. Matt Taylor and James Collins are both recalled, while Antonio Nocerino and Winston Reid both drop to the bench.
4.45pmMan Utd manager David Moyes opts to make six changes to his starting XI after Wednesday's victory over Olympiacos in the Champions League last 16. Darren Fletcher, Alex Buttner, Shinji Kagawa, Juan Mata, Marouane Fellaini and Ashley Young have all been given the nod by the Scot. Patrice Evra and Danny Welbeck drop to the bench, where they will be joined by Nani. Interestingly enough, it looks like Michael Carrick will be playing in central defence for the champions.
Cardiff City 3-6 Liverpool Everton 3-2 Swansea City Hull City 2-0 West Bromwich Albion Manchesyer City 5-0 Fulham Newcastle United 1-0 Crystal Palace Norwich City 2-0 Sunderland
4.58pmAs you can see, it's been a frantic day of Premier League football with goals going in all over the country. However, those results do little in terms of what's at stake in this match. West Ham will go nine points clear of the drop zone with a win, while Man Utd will stay in seventh place even if they come away from the capital with the spoils.
5.06pmWest Ham's superb form in February (P4 W4) was enough for Sam Allardyce to be named Manager of the Month. However, the Hammers have had a dodgy March so far, losing against Everton and Stoke City. Man Utd have taken eight points from their last six league games, with two wins, two draws and two defeats in that time.
5.10pmHEAD TO HEAD: Man Utd have the superior record when it comes to past meetings between these teams, winning 57 times compared to West Ham's 39. There have also been 25 draws. The Hammers have failed to beat the Red Devils in their last six matches.
5.12pmIt was Man Utd who came out on top earlier this season, winning 3-1 at Old Trafford back in December. Danny Welbeck, Adnan Januzaj and Ashley Young were on the scoresheet for the champions that day, while Carlton Cole grabbed a late consolation for the visitors.
5.18pmWest Ham goalkeeper Adrian recently speaking to the club's official website: "It's an important game and a difficult game. I made my league debut against Manchester United at Old Trafford and since then we have gained more confidence, that's important.
"I think that with us playing at home it will make it a good game and we will try to win the three points.
"It was difficult to make my debut there, but here every match is difficult and you need the right mentality and concentration in every game because nobody gives you the three points for nothing."
5.21pmPREDICTION TIME: How do you see this one playing out? We here at Sports Mole can see a few goals at Upton Park with Man Utd coming away with a 2-1 victory. If it keeps up today's theme of thrilling action in the Premier League then we should be in for a treat.
5.25pmThe players are starting to emerge in the tunnel as we approach kickoff. There's already a great atmosphere inside the ground and that's about to cranked up a few notches.
1 minKICKOFF! The teams are out, the pre-match niceties have been completed and it will be Man Utd to get us underway. Here we go!
4 minIt's been a lively start to this match with both teams going on the offensive early on. Man Utd have a great opportunity to take the lead as Young's cross is met by the head of Fellaini, but the Belgian's effort is cleared off the line by Carroll of all people.
6 minCHANCE! Another decent opening for the champions sees Kagawa lead a counter-attack before offloading for Mata. The Spaniard had to shoot from a tight angle and it was an easy save in the end for Adrian. West Ham then go up the other end a win a couple of corners, though they fail to make anything of them.
7 minThat is a sensational goal from Wayne Rooney to give Man Utd the lead! What a finish! The striker was just inside the West Ham half when he allowed the ball to bounce before hitting an incredible half-volley that goes over the head of the stranded Adrian and into the net. Amazing.
10 minYELLOW CARD! The first booking of the match goes the way of Man Utd's Rafael after the full-back bundled Downing to the ground with West Ham looking to break.
13 minDavid Moyes is sure to be pleased with the performance of his players so far. The Red Devils have been full of energy and are really taking the game to West Ham. That said, the hosts are still posing a threat up front with Carroll proving to be a handful for Jones and Carrick.
15 minCHANCE! Close for West Ham! Downing does brilliantly down the left as he runs past Rafael before floating a cross to the back post. It's Carroll who arrives late, jumping higher than Jones, but his header goes straight into the grateful arms of De Gea.
18 minOne area that West Ham might be keen to exploit is Rafael at right-back. The Brazilian has already been booked and hasn't started this match particularly brightly. West Ham are having a decent spell at the moment, though Man Utd are still on top at Upton Park.
21 minJuan Mata is seeing plenty of the ball right now for Man Utd. He's playing in a very advanced position too. The visitors put together a slick passing move around the West Ham box but it counts for nothing as Rafael's poorly-judged pass misses Young and goes out of play.
24 minCHANCE! West Ham lose possession for the umpteenth time inside their own half, allowing Mata to run at their defence. The Spaniard slips in Kagawa on the left side, only for the Japanese to have his low shot saved by Adrian. That could easily have been 2-0.
27 minThis is better from West Ham. The hosts are going for a more direct style now, testing Man Utd with some good crosses into the box. They appeal for a penalty when the ball bounces up onto Rafael, though Lee Mason waves away the tame appeals.
30 minSAVE! Man Utd are looking so dangerous on the break. This time it's Rooney who leads the charge, picking out Mata on the edge of the box. The Spaniard takes a touch before hitting a powerful strike towards goal but Adrian gets down low to push the shot away. The visitors desperately want that second goal.
33 minIt's that man again! Wayne Rooney makes it 2-0 but this time it was a fortuitous finish rather than a spectacular one. Young steamed down the right wing before seeing his cross cut out by Noble. However, the midfielder's clearance only went to Rooney, who prodded in from close range.
38 minYELLOW CARD! West Ham's James Tomkins now goes into the book for a cynical trip on Mata. No arguments there.
41 minMata continues to shine for Man Utd in that advanced position. It's as if he's been set free and is back in a position where he feels most comfortable. Either way, West Ham are struggling to keep a hold of him. His movement has been excellent and he's been involved in every attack for the champions.
45 minThere will be two added minutes at the end of this first half...
6.20pmLee Mason blows the half-time whistle, bringing an end to a great opening 45 minutes from a Man Utd perspective. Wayne Rooney gave the visitors the lead on eight minutes with a sensational half-volley before doubling their advantage on 33 minutes. West Ham have threatened at times, but it's not been enough.
6.23pmThere can be no denying that Man Utd deserve their lead. They've been excellent so far with their counter-attacking football. Rooney, Mata, Kagawa and Young have all played their part, giving West Ham multiple problems in the final third.
6.26pmWest Ham shouldn't been too disheartened with how they've played so far, but there are certain areas they need to improve on. For instance, they need to keep the ball better because Man Utd have been hitting them quickly on the break.
46 minSECOND HALF UNDERWAY! The players are back out and it will be West Ham to kick us off for the second half. No changes for either side at the break.
49 minIt's been a positive start to the second half from West Ham as they win a couple of corners. However, they can't make anything of them. Man Utd have also had a sniff of goal through Young, though Adrian was able to save his shot from the edge of the box.
52 minWe've yet to see Man Utd's counter-attacking prowess since the restart but they've done well to soak up plenty of West Ham pressure. The Hammers have an extra spring in their step and are looking to capitalise.
55 minIt's all hands to the pump for Man Utd at the moment as West Ham turn the screw. It's not pretty from the hosts but they've got their opponents worried. The champions are just having to hack the ball away at every opportunity before West Ham come back at them again.
58 minSUBSTITUTION: West Ham make their first change of the evening as Matt Jarvis enters the action in place of Mo Diame.
61 minIt's still West Ham who are on top as we pass the hour mark at Upton Park. The Hammers are looking a lot hungrier than what they did during the opening 45 minutes while Man Utd have dropped off in terms of their level of performance. The visitors are still proving tough to break down in defence though.
63 minSomething of a half-chance for Man Utd there as Young's deep cross is met at the back post by Fellaini, whose header goes high over the crossbar. It wasn't an easy opportunity for the Belgian with Collins marking him tightly.
66 minGary Neville isn't convinced that this game is done and dusted...
West Ham was always a ground where you felt something stupid could happen when we were playing there!
69 minWe're just starting to see Man Utd take hold of this match once more. They're being allowed plenty of time inside West Ham's half, giving them the chance to find their rhythm and play their way back into this contest. It's likely that West Ham are beginning to feel the strain a little bit after their flourish at the start of the half. Just over 20 minutes left to play.
72 minSUBSTITUTION: Another change for West Ham sees Carlton Cole replace Kevin Nolan. It looks like Sam Allardyce wants his team to throw everything at Man Utd during these final stages. Can they find a way back into this game?
75 minSUBSTITUTION: Now it's Man Utd's turn to shake things up as Wayne Rooney and Juan Mata are withdrawn for Danny Welbeck and Javier Hernandez.
78 minNothing doing for either side at the moment as the clock ticks down towards the 90-minute mark. Man Utd are just slowing the tempo down and keeping the ball while West Ham try to win it back. However, the Hammers look like a spent force.
81 minCHANCE! That should really be 3-0. Welbeck leads another quick counter-attack before finding Young out on the right side. The winger floats a cross in towards Hernandez but he gets too much on it and the ball goes over the Mexican's head. Meanwhile, West Ham make their final change as Antonio Nocerino replaces Matt Taylor.
84 minJames Tomkins is down receiving treatment after clashing with Fellaini. The pair both went for a 50-50 ball and it was the West Ham defender who came off worse. It looks like he'll be okay though.
87 minTime is running out for West Ham now. They've made a go of it in the second half but they've been unable to breach the Man Utd defence. There were plenty of questions before the match about whether Carrick would be able to cope at centre-back. Any fears from a Man Utd perspective were a waste of time because he's been very solid this evening.
7.23pmThe full-time whistle goes and it's Man Utd who come away with the points thanks to a 2-0 victory over West Ham. Wayne Rooney gave the visitors the lead on eight minutes with a spectacular long-range effort before doubling their advantage by half time. The champions had to defend for much of the second half but they were deserved winners in the end.
7.25pmThat's all from our live text coverage of this game but don't forget that you can keep up to date with all of the pots-match reaction right here on Sports Mole. Thanks for your company and we hope to see you again soon. Goodbye!