Arsenal made the breakthrough midway through the first half when William Saliba rose highest to head home from a corner. The Gunners' set-piece threat was evident again, underlining a key weapon in their title charge. Chelsea were then handed a lifeline when Piero Hincapie diverted the ball into his own net to level the scores before the break.

The decisive moment arrived in the 66th minute. Jurrien Timber powered in another goal from a corner to restore Arsenal's advantage, taking their tally from set-pieces this season to 16 league goals - equalling the Premier League record for a single campaign with nine matches still to play.

Chelsea's afternoon unravelled four minutes later when Pedro Neto was sent off. Already booked for protesting Timber's goal, he received a second yellow card for a late challenge on Gabriel Martinelli. It was Chelsea's seventh red card in the league this season and their second in successive matches.

Despite their numerical advantage, Arsenal were forced to dig deep. In added time, David Raya produced a superb diving save to deny Alejandro Garnacho's curling effort, while Liam Delap had a late equaliser ruled out for offside.

Arteta said: "The save that he made in the last action, from what ended up being an unbelievable shot, I got the right angle and my heart almost stopped. But David's hand was there to bring it back to life.

"I try to stay calm, but we weren't getting the dominance that we wanted against 10 men. You have to navigate through that. Everybody's suffering because the margins are so small."

The win marked Arsenal's second in a week after again being level at half-time, showing resilience at a crucial stage of the season.

Chelsea boss Liam Rosenior accepted responsibility for his side's indiscipline. "It is disappointing for Pedro, but it's not just him. As a group - me as a leader included - we have to take accountability," he said.

"You can fine players, but it is not about punishment. It is about finding the reason why. In the last two games we have caused our own issues, and if we don't eradicate it, it is going to cost us."

For Arsenal, however, this was another test passed – and another significant step towards ending a 22-year wait for the title.

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