Manchester City sustained the seven-point gap between them and leaders Manchester United after their first league win at Arsenal in 38 years, as referee Mike Dean sent off two players.
Laurent Koscielny's red card at 0-0 proved instrumental in City's win despite Edin Džeko having his penalty saved by Wociech Szczesny after Koscielny was dismissed for hauling the striker back.
James Milner however gave City a deserved lead on 21 minutes when he smashed a shot past the helpless Szczesny after Thomas Vermaelen dithered in the penalty area. It was City's first Premier League goal at Arsenal since DaMarcus Beasley's consolation in April 2007.
Džeko then did score 11 minutes later, tapping in from three yards out after Carlos Tévez's shot was parried by Szczesny with the expectancy that the Premier League champions would build on their lead.
Joe Hart enjoyed a relatively quiet afternoon as Arsenal rarely threatened his goal, but the Gunners were given a glimmer of hope when City captain Vincent Kompany also was red-carded in the 75th minute.
Kompany flew into a two-footed tackle on Jack Wilshere in an incident similar to his sending off against Manchester United in the FA Cup last year, and despite winning the ball will now face a three-match ban.
Arsenal however could not muster a tangible fightback and City ended their Emirates hoodoo.