It was Arsenal's second victory over Chelsea inside a week following their 2-1 FA Cup fifth round win on Sunday and again they came from behind to thwart Claudio Ranieri's third-placed side, who are now nine points off the pace.
Iceland striker Eidur Gudjohnsen, sent off on the hour for a second booking, fired Chelsea ahead after just 27 seconds at Stamford Bridge but replies in the first 20 minutes from Patrick Vieria and Edu gave unbeaten Arsenal the points.
Champions United, who started the day five points behind Arsenal, slipped further behind after relegation-threatened Leeds earned a draw at Old Trafford in another lunchtime kickoff.
