Chelsea missed the opportunity to strengthen their place in the top four as Emile Smith Rowe’s second Premier League goal in as many games gave Arsenal victory.
The game’s only goal came in the first half courtesy of a terrible mistake by Jorginho. The midfielder misjudged a pass back that was in danger of trickling over the line before Kepa Arrizabalaga managed to claw the ball away but only to Pierre-Emerick Aubameyang, who teed up Smith Rowe to slot in.
Chelsea dominated from then on as Mason Mount twice went close, seeing a volley inside the box blocked before the England international drew a good save out of Bernd Leno.
Christian Pulisic thought he had equalised on the hour but his strike was ruled out by the video assistant referee for offside, while substitute Olivier Giroud should have done better but swung wildly at his shot after a mistake by Mohamed Elneny.
The hosts then twice went agonisingly close to rescuing a point in stoppage time as Leno pushed Kurt Zouma’s header onto the bar before Giroud’s volley also bounced back off the woodwork, but Arsenal held on to take the three points.
The victory also meant the Gunners completed the double over the Blues for the first time in 17 years to boost their own hopes of ensuring they are playing European football next season.
Chelsea remain fourth on 64 points, six ahead of West Ham and seven ahead of Liverpool, who have two games in hand on Thomas Tuchel’s side.
Arsenal, meanwhile, are eighth and just one point behind Tottenham in seventh, although have played a game more.