Ole Gunnar Solskjaer’s side looked to have squandered two points when Solly March deservedly drew the home side level deep in stoppage time when he headed home at the far post.
United, however, responded by mounting one last attack and earned a corner thanks to a surging run from summer signing Donny van de Beek. Bruno Fernandes’ subsequent cross located Harry Maguire at the far post and he powered a header towards goal.
The flight of the ball was altered by the flailing arm of Neal Maupay but the full-time whistle had blown before the danger had been cleared by March, standing on his own goalline.
Maguire led United’s appeals and referee Chris Kavanagh was persuaded to visit the pitchside monitor, despite having already signalled the end of a dramatic contest.
The official quickly spotted Maupay’s offence and allowed Fernandes the opportunity to win a thrilling contest which, according to former Premier League official Peter Walton, was the correct decision.
He said: ‘The referee has got it right. I haven’t seen that before. In the laws of the game the only thing that the referee can extend the game for after the final whistle is the taking of the penalty kick.
‘Chris Kavanagh blew his final whistle, however the incident happened just before the final whistle and was allowed within law, and as I’ve said because the penalty was yet to be taken the referee within law has to allow time for the kick to be taken.’