Pedro Neto drilled in a fine equaliser as Chelsea and Arsenal both missed the chance to make up ground on Premier League leaders Liverpool following an entertaining draw at Stamford Bridge.
The result leaves the two teams on 19 points, nine adrift of top spot, and Arsenal without a win in their past five games in all competitions.
The visitors opened the scoring when Gabriel Martinelli slammed the ball past Blues keeper Robert Sanchez at his near post after collecting a back-post cross from the returning Martin Odegaard.
Chelsea’s leveller was deserved. Neto ran on to an Enzo Fernandez pass before cutting inside and striking a powerful low left-footed shot past David Raya’s dive.
England winger Bukayo Saka limped off late on with an injury as both sides strived to create a winning chance.
Arsenal came closest but Leandro Trossard was unable to divert William Saliba’s cross into the net from six yards, a second before referee Michael Oliver blew for full-time.
Chelsea have lost once in their past 10 matches and played like a team filled with confidence.
Cole Palmer set the tone when his long-range strike was tipped over by Raya before Malo Gusto headed a good chance over the bar from close range.
Martinelli also had a good chance in the first half before Kai Havertz had a strike ruled out for offside.