Bruno Fernandes claimed Manchester United's fans made the difference at Old Trafford after Erik ten Hag's side dumped Barcelona out of the Europa League.
The Portugal midfielder gifted Barca a first-half penalty with a foul on Alejandro Balde, with Robert Lewandowski beating David de Gea from the spot. United fought back after the break, though, with Fred equalising and substitute Antony firing home the winner.
The result means Man Utd are still in contention for four trophies. They will take on Newcastle United at Wembley on Sunday in the final of the Carabao Cup, while they're also five points behind Premier League leaders Arsenal and have an FA Cup fifth round game on the horizon.