Then, with 29 minutes played, any chance that West Brom had of getting back into the contest was ended when Claudio Yacob was handed a straight red card.

Here, Sports Mole has looked back over the contest to determine whether the home side were worthy victors.

Match statistics

Chelsea
Shots: 21
On target: 8
Possession: 74%
Corners: 15
Fouls: 7

West Brom
Shots: 5
On target: 1
Possession: 26%
Corners: 0
Fouls: 9

Was the result fair?

Unequivocally, yes. Even when the match was 11 vs. 11, Chelsea were the dominant force and they had already scored their opening two goals. They were sharper, brighter and quicker than their visitors all over the pitch. Had West Brom somehow managed to peg the Blues back at any stage, it would have been a travesty.

Chelsea's performance

With an away Champions League game on the horizon, Jose Mourinho will be delighted with this display. His side were gifted a couple of goals early on and, once West Brom were reduced to 10 men, it was far too easy. To Chelsea's credit, there was no hint of complacency and they continued to mount attacks throughout.

Mourinho has played down his side's chances of going the whole campaign unbeaten, but with the likes of Costa, Hazard and Oscar in this sort of form, it is going to take a very, very good side to stop them. That trio were lively throughout and seemed to carve open the West Brom defence at will.

West Brom's performance

Alan Irvine will not be hanging around at Stamford Bridge for too long after the final whistle. No doubt all week in training he would have demanded that his players kept things tight and maintained their concentration, but all that was undone with just 11 minutes played. Every time that Chelsea moved forward, the West Brom rearguard seemed to panic and lose their shape.

The sending off of Yacob made things even more difficult, and after that it was just about damage limitation. Fair play to them because they kept Chelsea at bay in the closing stages, although there was a feeling that the home team could have scored more had they really put their mind to it.

Sports Mole's man of the match

Ben Foster: He may have been the losing goalkeeper, but his performance between the posts prevented the match from ending in a cricket score. The West Brom stopper made a variety of saves to frustrate the likes of Costa, Hazard and even John Terry from scoring further goals. On a personal level, he will have impressed England manager Roy Hodgson with this showing.

Biggest gaffe

For parts of this season, West Brom have looked a well-organised unit and that is certainly what you need to be when you travel to Stamford Bridge. So, to give so much space to Costa in the 11th minute was criminal. Oscar's floated cross found the Spaniard, who had a good two to three yards of space, which allowed him to control the ball on his chest, before volleying in the opening goal. As far as West Brom were concerned, it set the tone for the remainder of the game.

Referee performance

The big decision for Lee Mason concerned the red card, which on initial inspection seemed harsh because Yacob did get the ball. However, the replays showed that he jumped into the challenge with Costa with both feet, which could have caused serious injury. So, it was the correct verdict from Mason, who officiated the remainder of the game well.

What next?

Chelsea: The Blues travel to Germany on Tuesday evening for a Champions League clash against Roberto Di Matteo's Schalke 04. Then, next Saturday, they make the long trip to Sunderland.

West Brom: Meanwhile, the Baggies face another London club on the same day as Arsenal travel to The Hawthorns.