Bellerin rescues a point for the Gunners in the London derby.
Arsenal suffered a double blow after David Luiz was sent off for challenge in the box.
Chelsea were awarded a penalty and Jorginho dispatched pass Leno to make it 1-0.
Gabriel Martinelli scored for the second game in a row after N’Golo Kante slipped and the teenage Brazilian raced and scored to level.
Chelsea looked to have gotten the winner after Cesar scored. But Hector Bellerin had other ideas.
Chelsea still stands 4th with just six points ahead of the Red Devils, who still have a game deficit.
Arsenal on the other hand are sitting in the 10th position.
Watch the Highlights below