Manchester United poured on the misery for flagging Premier League champions Manchester City as late goals by Bruno Fernandes and Amad Diallo snatched an unlikely 2-1 away victory from the jaws of defeat on Sunday.
Ruben Amorim's side were heading for a third consecutive league defeat as they trailed to Josko Gvardiol's header.
But a scrappy derby short of quality had a stunning late twist as a mistake by Matheus Nunes led to a penalty which allowed Fernandes the chance to level from the spot in the 88th minute.