The Gunners’ chances were dealt a severe blow midway through the first half when Luiz was sent off after taking out Tammy Abraham when he was through on goal after Shkodran Mustafi’s woeful backpass.
Jorginho made no mistake from the penalty spot to give the hosts the lead going into the break, but the Gunners hit back early in the second half through Gabriel Martinelli, who took advantage of N’Golo Kante’s slip to score his 10th goal of the season.
Chelsea thought they had nicked all three points when Cesar Azpilicueta bundled the ball home with six minutes remaining, but Arsenal leveled again just three minutes later through Bellerin to keep their slim chances of a top-four finish alive
A point keeps Frank Lampard’s side fourth, six points clear of fifth-placed Manchester United, who play Burnley on Wednesday. Meanwhile, Arsenal stay 10th, 10 points behind the Blues.