Hector Bellerin scored a late volley to draw earn Arsenal a share of the points as it looked as though Chelsea had beaten their London rivals on Wednesday night.
Bellerin's strike cancelled out Marcos Alonso's effort from close range following Eden Hazard's penalty and Jack Wilshere opener in the second half.
Sportsmail's SAMI MOKBEL watched on from the press box at the Emirates to pick out the best and worst performers on the pitch.
ARSENAL (3-4-2-1)
Petr Cech 8.