Brazilian forward Antony stepped off the bench to send Manchester United through to the Europa League last 16 as the hosts came from behind to beat Barcelona 2-1 in Thursday's playoff second leg and progress 4-3 on aggregate.
After a frantic start, Barca were awarded an 18th-minute penalty when Bruno Fernandes was adjudged to have fouled defender Alejandro Balde and Robert Lewandowski just squeezed the spot-kick home.
United came out for the second half looking like a different side and levelled through Fred, the Brazilian steering home Fernandes's pass two minutes after the break.
A superb save from goalkeeper David de Gea kept out an effort from Barca's Jules Kounde, a stop that proved crucial as Antony arrowed a superb finish into the bottom corner 17 minutes from time to send United through.
United remain in four competitions this season as they bid to win their first major trophy since 2017.
"The belief of the team is always there," Fernandes told BT Sport. "The belief of the fans, they push us through difficult moments.
"We have made great comebacks, the club is made also by that. In the past we have done a lot like this result."
Both sides have improved a great deal under their new coaches this season, with some of the football in the first leg testament to that and setting the tie up nicely for the return fixture under the lights at Old Trafford.
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