Arsenal beat Tottenham Hotspur 3-0 in the first ever London derby at the Emirates Stadium.
The Gunners broke the deadlock with a composed finish by Emmanuel Adebayor, and two penalties followed, both converted by Gilberto Silva.
The win extended Arsenal’s unbeaten run over Tottenham Hotspur to 14 league matches.
It left Arsene Wenger’s side in third place on 25 points, 16 points behind leaders Manchester United, with Spurs 10th on 22 points.
Sebastian Larsson scored a stoppage-time winner as Birmingham City triumphed 3-2 away against Tottenham Hotspur in Alex McLeish’s first match as manager.
Gary McSheffrey’s penalty gave Birmingham the lead, only for Robbie Keane to level with a spot-kick of his own and then put Spurs ahead three minutes later.
But Cameron Jerome made it 2-2 and Keane was then sent off, leaving McLeish’s side in the ascendancy - and Larsson struck decisively in the 92nd minute.
The result left Spurs 16th on 12 points, a point above the drop zone, while Birmingham moved up to 12th on 14 points - still only three points from relegation.