Joe Cole's late winner settled a scrappy encounter against former club West Ham and kept Chelsea in touch with the Premier League pace-setters.
Cole raced on to Didier Drogba's header after 76 minutes and rounded West Ham keeper Robert Green to score as the visitors appealed in vain for offside.
It was the decisive moment in an ill-tempered game littered with stoppages at Stamford Bridge.
Nolberto Solano came close for West Ham, but Chelsea claimed the points.
606: DEBATE
The first half was an utterly wretched affair, characterised by petty fouls, heavy challenges and some obvious score-settling on the part of players from both sides.
What the game did not have - until the goal - was genuine quality, apart from one curling effort from Drogba that drifted just wide and a Solano lob that landed on top of the Chelsea net.
The ill-feeling started when Luis Boa Morte aimed a needless kick at Chelsea keeper Carlo Cudicini - with England captain John Terry almost inevitably getting involved in the ensuing fracas.
Mikel Jon Obi was then booked for a wild tackle on Scott Parker, and he was swiftly joined by Salomon Kalou after he lunged at Boa Morte on the touchline.
West Ham's Parker was lucky not be cautioned by referee Howard Webb for a couple of late challenges, while Boa Morte's persistent offending was finally punished seconds before the break for a foul on Mikel.
The second half had to be better, and Chelsea almost made the perfect start when Wayne Bridge played in Steve Sidwell, but his goal-bound drive was blocked by Matthew Upson.
West Ham were having success in keeping Chelsea at arm's length, and carved out a chance of their own on the hour, but Boa Morte's shot was partially blocked by Terry and Cudicini saved comfortably.
As the game opened up, West Ham keeper Robert Green did well to claw away Cole's cross with Drogba waiting to pounce.
And it was Cole who finally broke the deadlock with 14 minutes left, although West Ham were left complaining bitterly as Chelsea celebrated.
West Ham felt Cole was offside as he raced on to Drogba's header, but the flag stayed down as he showed great composure to round Green and finish into the top corner.
"It was not an easy game - West Ham defended very well.
"In the first half we played the game the way West Ham wanted us to play, but in the second half we changed and played the way we wanted to.
"We didn't create many chances in the first-half, but once we scored we might have got a couple more goals. We deserved to win."
"If we keep going like that we will be OK.
"We set out our stall - we had a plan - and it held us in good stead, but we just didn't have enough to fashion that one chance.
"I'm a bit disappointed. I thought we deserved a draw as we had a great work ethic - there were plenty of positives."
Chelsea: Cudicini, Belletti, Alex, Terry, Bridge, Sidwell (Wright-Phillips 66), Obi, Lampard, Kalou, Drogba, Joe Cole (Makelele 89).
Subs Not Used: Hilario, Shevchenko, Ben-Haim.
Booked: Obi, Kalou, Belletti, Lampard, Terry.
Goals: Joe Cole 76.
West Ham: Green, Neill, Gabbidon, Upson, McCartney, Solano (Ljungberg 74), Parker (Spector 79), Mullins, Etherington (Ashton 79), Boa Morte, Cole.
Subs Not Used: Wright, Collins.
Booked: Etherington, Solano, Boa Morte.
Att: 41,830
Ref: Howard Webb (S Yorkshire).
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