The Red Devils bounced back from 1-0 down to win 3-2, talisman Cristiano Ronaldo grabbing two goals in the second half to make it a perfect farewell for Michael Carrick.
It was an enthralling encounter under the lights at Old Trafford, a match which featured one of the most bizarre goals in Premier League history.
Early in the first half, Arsenal's Emile Smith Rowe fired the ball into the back of the net on the volley while David De Gea was down injured after United had cleared a corner.
On first viewing, it looked as if the goal would be rightly disallowed, but it turned out that De Gea was fouled by his own man, Fred.
And the fact that Martin Atkinson didn't blow his whistle until after the ball had gone in meant that it was deemed legal following a VAR review.
Video: Smith Rowe's goal vs Man Utd
It was absolute chaos for a few minutes at Old Trafford on Thursday and the incident didn't exactly paint De Gea in the best light.
While Fred accidentally stepping on his foot must have been painful, the Spaniard should certainly have tried harder to get back to his feet and protect the goal.
Paul Scholes certainly agrees with that take, the United legend labelling De Gea as "embarrassing" when analysing Smith Rowe's controversial strike.
“That’s embarrassing. You protect your goal, you do anything to stop a goal,” Scholes said, per Evening Standard.
“To turn away, to not even look, there’s clearly nothing wrong with him. He’s done himself. De Gea should be there, protecting his goal at all times. It doesn’t look that bad to me. The goal had to stand.”
He isn't one for sitting on the fence is Paul.
Manchester United 3-2 Arsenal Reaction | Football Terrace
Fellow pundit Ian Wright was also far from impressed with De Gea and is convinced the United goalkeeper was not seriously hurt.
“When you see David De Gea after the goal, he’s so incensed that he sprints after the referee,” he said.
“My problem with that is there’s not enough seriously wrong with him to go down. For me, that’s embarrassing.
“De Gea should be getting up after that to try to save it and then go down after if there is something wrong with you."
It's hard to argue against the points raised by Scholes and Wright to be honest. De Gea must be feeling mighty relieved that Ronaldo made sure his actions weren't at all costly in the end.