Arsenal revived their hopes of a top-four finish with first-half goals by Alexandre Lacazette and Laurent Koscielny securing a comfortable 2-0 derby win at home to Chelsea on Saturday.
Victory, only Arsenal's third at home in the league against Chelsea in 10 years, left them in fifth place but cut the gap on their fourth-placed rivals to three points.
A scintillating first half saw chances galore for Unai Emery's side who began the match in sixth spot after Manchester United's earlier win against Brighton and Hove Albion.
Pierre-Emerick Aubameyang should have scored early on but sliced wide from in front of goal but strike partner Lacazette was more clinical with a superb opener after 14 minutes.
Arsenal doubled their lead in the 39th minute when skipper Koscielny mistimed an attempted header but the ball came off his shoulder and beyond Chelsea keeper Kepa Arrizabalaga.
Marcos Alonso headed against the post on the stroke of halftime for Maurizio Sarri's side who were perhaps fortunate not to be further behind at the interval.
Arsenal restricted Chelsea in the second half as the visitors enjoyed the lion's share of possession without ever opening up Arsenal's defence.
Not even the introduction of former Arsenal striker Olivier Giroud could liven up Chelsea's blunt attack.
The one sour note for Arsenal was the sight of Spanish right back Hector Bellerin leaving the field on a stretcher with what appeared to be a knee injury.