Arsenal regained second place in the English Premier League on Monday with a 3-1 win over Chelsea that dealt a blow to the champions' title hopes in a dramatic London derby at the Emirates Stadium.
Arsene Wenger's side had repeatedly failed to produce the goods in crunch matches against their London rivals, but they finally rose to the occasion as goals from Alex Song, Cesc Fabregas and Theo Walcott gave them a vital victory at the Emirates Stadium and their their first against Chelsea since November 2008.
"We didn't think about the past," said Walcott after helping Arsenal end a run of five straight defeats by Chelsea. "Everything went well. We made Chelsea look average at times. We played some great football and wanted to do it for the fans because in recent years against Chelsea we've been disappointing."
Victory saw Arsenal move to within two points of leaders Manchester United and go second on goal difference above Manchester City. Chelsea's fifth league defeat of the season left the fourth-placed Blues six points adrift of United, having played one game more.
Arsenal manager Arsene Wenger, whose side last won a major trophy in 2005, insisted: "We have matured. We have been disciplined, matured and played for each other."
"Let's hope that it strengthens our belief that we can challenge for the championship and it strengthens our belief we're on the right way," the Frenchman added.
The Gunners looked hamstrung by nerves during a tame 1-0 defeat against United in their last match and Wenger knew they needed a more dynamic performance this time. Wenger's players rose to the challenge in impressive fashion and controlled possession right from the start. Samir Nasri brought Chelsea goalkeeper Petr Cech into action for the first time with a long-range free-kick.
Wenger's side kept probing and Robin van Persie blazed over before Cech plunged at Walcott's feet to block the winger's shot. It took an even better save from Cech to keep Chelsea on level terms when he stretched every sinew to tip over Nasri's deft chip. Arsenal's pressure finally told in the 44th minute as Song surged into the penalty area after playing a one-two with Jack Wilshere. The ball broke towards Fabregas and, as the Arsenal captain collided with Paulo Ferreira, Cameroon midfielder Song seized his chance and drove a low shot past Cech.
Lampard's presence in the Chelsea starting line-up for the first time in four months after hernia and groin injuries was supposed to inspire the Blues, but the England midfielder was well off the pace. If Ancelotti read the riot act at half-time, he must have been sorely disappointed with the response from his lacklustre stars. In the space of 90 seconds, two sloppy pieces of Chelsea defending presented Arsenal with the goals that put the result beyond doubt.
First, Michael Essien's 51st minute tackle on Fabregas sent the ball into Walcott's path. Walcott was then granted too much space by former Arsenal defender Ashley Cole and he was able to sprint clear before sliding a pass to Fabregas, who stroked his shot past Cech. Arsenal were rampant now and, with Chelsea looking more shambolic by the second, Walcott took full advantage as he caught Florent Malouda in possession and flicked a pass to Fabregas.
The Spaniard's return ball put Walcott through on goal and he drove a fine finish into the far corner of Cech's net.
Even when Branislav Ivanovic reduced the deficit by heading Drogba's free-kick home in the 57th minute, there was little realistic hope of a Chelsea comeback as Arsenal cruised to their most important win of the season.
Chelsea's loss added to the pressure on Italian manager Carlo Ancelotti, whose side are being pushed hard by the likes of Tottenham and Bolton for a top four finish, and with it a place in next season's UEFA Champions League.