In a thrilling game between two of the league’s high-flyers, United took a first-half lead through a header from Anthony Martial.
Villa came out firing in the second half and were quickly rewarded when Bertrand Traore equalised but minutes later Villa were pegged back again by Bruno Fernandes, who scored from the spot.
The award of the penalty has courted much controversy.
Paul Pogba went down after close contact from Douglas Luiz, but replays are inconclusive over whether the Frenchman tripped himself.
VAR didn’t overturn referee Michael Oliver’s decision and Fernandes’ bottom-corner strike proved the difference.
Former Arsenal goalkeeper Emiliano Martinez let his feelings known after the match.
Responding to a tweet that said Pogba had fould himself, Martinez wrote, ‘Highlight of the game’ accompanied by an angry face emoji.
Luiz, who was the man accused of fouling Pogba, was incensed by the decision.
‘I always support fairer football, with fewer mistakes, but then I stop and see these types of moves.
‘If we have VAR to help, LET’S start using it CORRECTLY, these mistakes can define the future of clubs!’
He then posted a clip that appears to show Pogba tripping himself, with the caption: ‘This just to show it more clearly’.
Luiz, the Brazil international, also retweeted a clip of Pogba telling United team-mate Luke Shaw to dive.
Dean Smith, the Aston Villa manager, shared the thoughts of his players.
‘I thought it was a penalty at the time, but I looked at it after the game and saw he tripped himself, he told Sky Sports. ‘I don’t see why Michael (Oliver) couldn’t have looked at it.
‘That’s what VAR is for isn’t it? He’s tripped himself up. There’s margins in football. I’ve seen it again, and I don’t think it’s a penalty.’