Freddie Ljungberg's deflected shot sank Tottenham Hotspur in the North London derby and increased Arsenal's lead at the top of the table.
Arsenal's win puts them four points ahead of Chelsea and five clear of Manchester United, who both play on Sunday. The leaders remain the only unbeaten team in the Premiership.
Ljungberg's 79th-minute effort looped off Stephen Carr and left Spurs keeper Kasey Keller stranded. The Swede's goal capped a second-half rally by the Gunners after Darren Anderton gave Tottenham a fifth minute lead.
Robert Pires levelled in the 69th minute, sweeping in the rebound after Keller palmed out Thierry Henry's left-foot shot.
The equaliser gave Arsenal fresh impetus just when they seemed to be running out of ideas. Spurs' defensive midfielders Ledley King and Stephane Dalmat had clamped down on the Gunners, who clearly missed the injured Patrick Vieira.
Anthony Gardner was outstanding at the heart of the visitors' defence.
Tottenham's caretaker boss David Pleat had fielded a team to frustrate Arsenal, but they grabbed a shock lead when Anderton poked the loose ball past Jens Lehmann after Robbie Keane's shot ricocheted around the box.
Keller made two spectacular saves from Henry and beat out a Pires cross-shot. Gilberto and Kanu shot wide.
At the other end, Lehmann twice had to save smartly from Helder Postiga after poor backpasses by Lauren.
But Tottenham failed to capitalise and slipped back towards the relegation zone and they have failed to beat Arsenal in the last nine meetings.