A confidence-boosting 4-1 win against rivals Tottenham was the perfect tonic for Arsenal, whose recent dropped points had seen Manchester City close in on the league leaders.
Nonetheless, it was the visitors who created the first genuine chance of the game, with Mamadou Sarr – making his first league start for Chelsea – finding himself in a promising position from a set-piece delivery, only to miscue off-target.
At the other end, Robert Sanchez wasn’t looking entirely comfortable, and he was almost caught out in spectacular fashion as Eberechi Eze’s lofted attempt from near the halfway line dropped marginally wide.
Despite this, Liam Rosenior would have been largely content with the start his side had made, but that good work was undone when Gabriel Magalhaes won a header at the back post to redirect the ball across goal, where William Saliba nodded home.
Undeterred, Chelsea came agonisingly close to levelling before half-time when David Raya clawed away what would have been a Declan Rice OG, but just moments later, the resulting corner found its way into the back of the net via Piero Hincapie, who inadvertently helped on Reece James’ cross over the line.
Aiming to make it 19 wins in their last 26 Premier League London derbies (D6, L1), the onus was on the hosts to retake the lead as the second half got underway.
However, it was Chelsea who were threatening to go ahead as Enzo Fernandez tested Raya with a drilled strike before Joao Pedro kept the goalkeeper alert with a close-range header.
Perhaps struggling to wrestle back their advantage, Arsenal benefited from yet another corner – a league-high 16th – to restore their lead, with Jurrien Timber meeting Declan Rice’s delivery to beat Sanchez.

Just four minutes later, the Blues were in an uncomfortably familiar situation as they were once again reduced to 10 men, adding to the worst disciplinary record in the league as Pedro Neto was dismissed for a second yellow card, taking out Gabriel Martinelli on the break.
That proved to be the nail in the coffin for Chelsea, whose depleted side couldn’t muster another equaliser, seeing Raya away an Alejandro Garnacho cross-shot and Liam Delap have a goal ruled out for offside in the closing stages.

Arsenal are now unbeaten in six league games (W4, D2), five points clear of Man City, who have a game in hand in an increasingly engrossing title battle.
As for Chelsea, a valuable point in the race for UEFA Champions League qualification slips through their fingers, ending Rosenior’s unbeaten league start after seven games (W4, D2).
Flashscore Man of the Match: Reece James (Chelsea)

