Goals from Anthony Martial and Jesse Lingard cancelled out strikes from Shkodran Mustafi and Alexandre Lacazette as the two sides put on a breathless show that you couldn’t take your eyes off.
The Reds' pursuit of the Premier League's top four took a hit four days earlier at St Mary’s and both Mourinho's shaken-up United side, showing seven changes from Saturday, and the fans knew that the rejuvenated Gunners had to be stopped from stretching further ahead in fourth place.
Arsenal have responded to the exit of long-time manager Arsene Wenger in positive fashion with new boss Unai Emery engineering a 19-match unbeaten run in all matches this season since two opening Premier League defeats.