However, in the last minute of stoppage time, Eden Hazard converted a controversial penalty to secure a share of the spoils for the home side.
You can find out how the match unfolded with our minute-by-minute updates below.
5pmThat's all we have time for from Stamford Bridge. Thanks for joining us this afternoon. Until next time, goodbye.
4.59pmWell, after a largely dull first half, the second 45 minutes was entertaining. Chelsea have stolen a point thanks to a penalty that should never have been given. West Brom are frustrated and you can understand why.
90+5 minAn absolute shocker from referee Marriner, who gives a foul against Stephen Reid, despite the fact that Ramires was already on his way down. It was never a penalty, but the referee gives it and Hazard steps up to score from 12 yards. Chelsea may have got lucky, but they've got a share of the spoils.
90+2 minCHANCE! What an opportunity for West Brom to secure the points as Brunt breaks clear. He has Anichebe to his left and Morrison to his right, but he goes for goal from 12 yards out. He can only fire well over the target, though. Will that error be punished?
90 minChelsea have four minutes of stoppage time to salvage something from this game.
89 minSUBSTITUTION: An unsurprising defensive switch from Clarke as he brings off winger Amalfitano and sends on full-back Goran Popov. It means that the Baggies have gone to five at the back, with Ridgewell becoming a centre-back alongside McAuley and Olsson.
88 minCHANCE! Ba could have been a Chelsea hero, but he somehow fails to make a connection with Cahill's low cross. Any sort of touch would surely have drawn the home side level, but he completely missed the ball as he slid in and West Brom survive again.
84 minBOOKING! West Brom's Amalfitano gets his name taken for a late challenge on Ramires. The resultant free kick is hoisted into the area by Mata, but once again the West Brom defence clears the danger.
82 minSUBSTITUTIONS: It's West Brom's turn to make some switches as Shane Long, who has ran for the cause all afternoon, is replaced by Victor Anichebe. Sessegnon also comes off, with James Morrison taking his place. Moments later, Willian heads over for Chelsea when he really should have done better. Time is running out for the home team.
78 minSAVE! How are Chelsea not level? Some sustained pressure sees the Blues camped inside the West Brom box. Branislav Ivanovic has a powerful shot parried clear by Myhill, before Ramires's shot is deflected into the side netting. From the resultant corner, Terry has a volley blocked and West Brom can breathe again.
77 minWorrying moment for Chelsea, who have used up all their substitutions. Hazard falls to the ground and was clutching his knee. He's up after some treatment from the physio, but he's moving rather gingerly right now.
74 minSUBSTITUTIONS: It's time for Mata as he replaces Oscar. It's actually a double change from Mourinho, who also throws on John Obi Mikel in place of full-back Azpilicueta. That's all of Chelsea's substitutions done.
68 minWest Brom won at Old Trafford earlier in the campaign and now they lead at Stamford Bridge. It's Ridgwell of all people that sets up Sessegnon on the edge of the area. The playmaker then drops his shoulder to create some space, before poking the ball towards goal. Cech should save it, but it squirms under his hand and into the net. The away fans are jubilant - over to you Chelsea!
67 minIt must be said that Chelsea have reacted positively to being pegged back. Ba's presence has given the West Brom defenders something extra to deal with. They've forced a couple of corners, but so far the Baggies have defended well. They just need to keep Ridgewell out of the action!
65 minSUBSTITUTION: First change for Chelsea and it's Lampard that comes off. I have to say that the veteran seems to lack the mobility to play in a holding role. Anyway, he has been replaced by Demba Ba, who will join Eto'o in attack, while Oscar drops a little deeper into the midfield.
61 minLong showed his credentials in the air moments ago, but Chelsea failed to take that lesson on board and have been punished. First centre-back Gareth McAuley powers a header at goal, but Cech gets behind the ball to deny the defender. It flies straight up in the air, though, and Long leaps highest to nod the ball into an empty net. West Brom have been more positive after the restart and they've been rewarded. Game on.
57 minOFF THE POST! Oh so close for West Brom, who finally have a decent effort at goal. Amalfitano sends over a cross from the right for Long, who leaps highest in a crowded penalty area. He sends his header downwards, but it cannons against the upright before being cleared to safety. Encouragement for Albion nonetheless.
55 minUnfortunately, very little has changed from the first half. Chelsea have controlled the possession, but there is a slow tempo about their play and moves are breaking down far too frequently.
50 minA collector's item as Hazard's first touch evades him. He's released by a great pass over the top of the West Brom defence from Oscar, but the usually assured Chelsea playmaker cannot get the ball under control and Myhill is able to collect. Had his touch been a better, a goal looked inevitable.
46 minSECOND HALF UNDERWAY! West Brom gets us restarted at the Bridge. Let's hope that it's a more lively 45 minutes.
4.02pmIt seems an unlikely that either manager will consider making a change just yet, but if Chelsea continue to struggle (despite their lead), Mourinho could well turn to Mata, who possesses that ability to create chances at the drop of a hat.
3.59pmClarke is also likely to be unhappy at the break, but not with the performance of his players. They obviously came with a game plan to frustrate the hosts and it was working perfectly until Ridgewell dallied inside his own area. It's likely that he will be given a verbal dressing down right about now!
3.56pmDespite the late goal, Mourinho is bound to be disappointed with the way that his side has played. They've had more than enough of the ball, but there has been a lack of conviction in the final third. A mistake from West Brom looked to be the only way that they were going to score and that's what happened just before the break.
3.53pmWell, had that 45 minutes been played in your back garden, you could have been forgiven for drawing your curtains. It certainly wasn't one for the purists.
45+2 minBOOKINGS! A yellow card apiece in quick succession as Eto'o is booked for his over-exuberant celebration, while West Brom frontman Long is cautioned for clattering into the back of John Terry, who goes down as if he's been shot.
45 minLiam Ridgewell will not want to see this goal back. Hazard does well initially as he cuts in from the left and drills a shot towards goal. Myhill reacts by getting down and pushing clear the effort. The ball drops to Ridgewell, who delays his clearance and Eto'o nips in to poke the ball into an unguarded net. The West Brom defender had a good second or two to clear the danger! Great time for Chelsea to score.
41 minLong has barely touched the ball for West Brom. He just looked to get beyond the Chelsea rearguard as the visitors counter-attacked, but Youseff Mulumbu's cross-field pass was poor and Gary Cahill easily cleared the danger as Long lurked.
37 minCHANCE! Oscar has just summed up this half from a Chelsea point of view. The home side steal possession deep inside West Brom territory and break forward with intent. The ball is worked to Oscar, who takes one touch to open an opportunity for himself 18 yards from goal. His shot, though, ends up in the second tier behind the goal.
33 minMore good goalkeeping from Myhill as he hurries off his line to punch clear Lampard's inswinging cross. His clearance falls to Hazard, but the Belgian cannot adjust his feet quickly enough and Jonas Olsson mops up the danger for West Brom. Better from Chelsea, though, because they are showing a bit more intent.
30 minSAVE! From the resultant free kick, Oscar steps up and curls the ball goalwards. It is heading for the top corner, but there isn't enough pace on the Chelsea midfielder's effort and Boaz Myhill scampers across his line to tip the ball away from danger.
29 minBOOKING! Well, that's been coming. Yacob again commits a foul, this time on Hazard. He can have no complaints because he was warned earlier on.
26 minIt's just not happening for Chelsea at the moment. They are getting to a certain point (around 25 yards from goal), but then there is a real lack of imagination. Now, if only they had a Spanish World Cup winner who had a real creative edge to his game on the bench...
21 minVery poor from Brunt, who just found himself with time and space on the West Brom left flank. He had two players in the box to pick out, but his cross is far too close to Petr Cech and the Chelsea keeper collects with ease. Brunt is usually dangerous from that sort of area.
16 minBOOKING! It's not Yacob, but Frank Lampard that sees yellow. It ends a poor period for the veteran Chelsea midfielder, who saw his free kick crash into the West Brom wall. Then, he lacks the pace to catch Long on the counter-attack and so he opts to bring down the West Brom striker. He doesn't argue, it was a clear caution.
14 minClaudio Yacob needs to be careful, because he's just been pulled up for a second time after committing a foul on Chelsea midfielder Oscar. It appeared that Andre Marriner warned him that one more poorly timed challenge would result in a booking.
9 minStill very little happening here. Chelsea are stroking the ball around the pitch nicely enough, but we haven't seen much of Eto'o. Meanwhile, up the other end Amalfitano has just shot well wide from distance. This game needs a spark from someone.
4 minVery little to report during the opening exchanges, although it's been Chelsea, as you'd expect, that have dominated the possession. The reinstated Hazard has been lively - it seems that he has a point to prove!
1 minGAME ON! Here we go then. Chelsea, attacking from right to left, get us underway at Stamford Bridge.
2.57pmTelevision cameras have just captured Mourinho and Clarke walking out to the dugouts together, sharing a joke as well. It's unlikely that things will be that friendly during the 90 minutes!
2.53pmA bit more from Twitter, this time from Chelsea, who have just made us aware of a certain milestone for Mourinho:
2.49pmPREDICTION: Right, with around 10 minutes to go until we are off and running, let's have a go at predicting the outcome. While football is not played on paper, West Brom's record at Stamford Bridge cannot be ignored. What's more, Chelsea rarely lose back-to-back Premier League games. Mourinho is bound to demand a reaction and you'd expect him to get one. With all that in mind, let's say 2-0 to the hosts.
2.44pmWhere would we be without Twitter? Not inside the Chelsea dressing room, that's for sure:
2.40pmFrom West Brom's last five trips to West London, they've lost all of them, shipping 15 goals in the process. During that time, they've only found the net themselves once. In fact, as mentioned in the introduction, the Baggies have not won away at Chelsea since 1978.
2.36pmWhen you look at the previous meetings between these sides at Stamford Bridge, the smart money would be on a Chelsea win. Brace yourselves West Brom fans...
2.31pmHaving said that, Clarke is determined to put friendships aside for 90 minutes, having expressed his determination for visiting Albion to claim all three point: "I want to get a positive result for Albion. Jose is in the opposition dugout but it doesn't change what I want to get from the game. I said before that Chelsea has been a big part of my career.
"I was there for a long time as a player and as a coach, but I have to be selfish and this week it's been me preparing Albion to go to Stamford Bridge, hopefully to disappoint Jose, and that's all I'm focused on."
2.28pmReturning to the Mourinho-Clarke relationship, here is what the latter has recently said about it: "I don't speak to [Jose] every week or text him every week but the friendship is good. I think when you've worked with somebody closely you build a bond and you take that bond through the rest of your life. But I haven't seen him for well over five years. So it will be nice to catch up with him face to face as opposed to little text messages."
2.25pmA potential blow for Chelsea in the left-back department has been landed by Luke Shaw this afternoon. Reports have strongly linked the Blues with the England Under-21 international, but writing in Southampton's matchday programme, the youngster has rubbished the speculation:
"I don't take much notice of things that are written about me - it is frustrating at times but I just laugh it off. I've signed a contract at Southampton and not even thinking about moving. I'm happy here because I'm playing football."
That's probably music to Azpilicueta's ears!
2.23pmStaying with Mourinho, he's caused a bit of a surprise today by not selecting Ashley Cole at left-back and instead picking Azpilicueta, despite the fact that the Spaniard is a natural right-back. Whether Cole is carrying a knock we don't know, but Mourinho has been full of praise for Azpilicueta of late. Perhaps a sign that Cole is no longer an automatic starter at the Bridge?
2.20pmThe two managers of course have some history, having worked together when Mourinho was first in charge of the Blues. The Portuguese coach has conceded that his former assistant, Steve Clarke, is likely to make life hard for him today:
"I am very happy to meet Steve Clarke again," BBC Sport quotes Mourinho as saying. "It will be a difficult game because he organises his teams well. Every game Steve Clarke plays I wish he will win, but tomorrow that is not the case which is strange."
2.17pmShane Long will feature as a lone centre-forward for the Baggies, who will use Morgan Amalfitano, Stephane Sessegnon and Chris Brunt in attacking midfield roles. Youngster Saido Berahino has been forced to settle for a place among the substitutes, but former Chelsea striker Nicolas Anelka misses out altogether because of injury.
2.12pmAnd here comes the away side's starting lineup...
2.11pmSo, the big news for Chelsea is that Eden Hazard starts after he was left out completely against Schalke 04 on Wednesday night. The Belgian had been dropped by Jose Mourinho following his failure to turn up to training on Monday. Elsewhere, Samuel Eto'o continues up front in the absence of the injured Fernando Torres, while Cesar Azpilicueta keeps his place at left-back.
2.09pmCHELSEA SUBS: Schwarzer, Cole, Luiz, Mikel, Mata, De Bruyne, Ba
2.05pmAccording to Chelsea's official Twitter feed, the teams news from the Bridge is just a couple of minutes away. Bare with us...
2.03pmAfternoon all. Make the most of today, because an international break is upon us, meaning there will be no Premier League football next weekend. Here, we will be covering Chelsea's home clash against West Bromwich Albion.