In stoppage-time, one of England's many heroes at Euro 2020 gave away a penalty after he handled the ball while attempting to block a cross.
West Ham manager David Moyes decided to bring on his captain Mark Noble to take the spot kick, a decision that's been heavily criticised in the aftermath of the eventful match.
Noble's weak effort on goal from 12 yards - which was his first touch of the ball - was saved by David de Gea, sparking scenes of joyous relief among the United fans in attendance.
The Red Devils players on the pitch were also noticeably jubilant, but they had to contain their excitement due to the fact the game hadn't finished.
One player who nearly forgot that the match wasn't over when De Gea thwarted Noble was Shaw himself and his comical reaction to the goalkeeper's heroics was captured by a fan in the stands.
West Ham United vs Manchester United Reaction | Football Terrace
The left-back ran over to celebrate with De Gea and before the shot-stopper turned around, Shaw realised the game was still going and had to check his run just a few inches away from the Spaniard.
De Gea didn't even seem to realise as the defender ran past his goal...
Video: Shaw's reaction to De Gea's penalty save
Where would we be without fan footage, eh?
Shaw's run in that video is giving us serious Forrest Gump vibes to be honest.
It would have been cruel if the left-back's handball was what ended up costing United two points in east London, as he was one of the best players on the pitch throughout the game.
Shaw was a constant threat in attack and looked pretty solid in defence up against the Hammers' array of talented forwards.
After a few sub-par years under Jose Mourinho, the former Southampton man is finally fulfilling his enormous potential and it's great to see.