Zlatan Ibrahimovic's late winner won the EFL Cup for Manchester United and gave manager Jose Mourinho his first major trophy since he took the job in the summer, as brave Southampton were beaten at Wembley Stadium in London.
Southampton were the better side for most of this final but were left heartbroken by a header from the 35-year-old Swedish striker Ibrahimovic, as he took his tally to 26 goals this season.
In the first half, Southampton striker Manolo Gabbiadiani saw a goal wrongly ruled out before United took a two-goal lead through Ibrahimovic's superb 19th minute free-kick and Jesse Lingard's neat finish seven minutes before half-time.
Southampton got back to 2-2 after two quick strikes from Gabbiadini either side of half-time.
Oriel Romeu hit the woodwork before Ibrahimovic scored from Ander Herrera's cross three minutes from time to give United a victory.
Manchester United manager Jose Mourinho:
"Honestly, Ibrahimovic won the game for us because he was outstanding. I can see a couple of performances - Pogba similar level - but he was outstanding. In a match where the opponent was better than us for long periods - they deserved to go to extra time - he made the difference and he gave us the cup."
Southampton manager Claude Puel:
"We came back with quality. Perhaps we deserve better. It's football and congratulations to Manchester United and their players. Manolo Gabbiadini scored three good goals [including the disallowed goal]. There's a lot of disappointment of course. We had a fantastic game without the reward. I hope we can continue on this level."
It means Jose Mourinho has won this trophy four times now, which only two other managers have done: Sir Alex Ferguson and Brian Clough.