Zlatan Ibrahimovic's late header secured Manchester United the first major trophy of the Jose Mourinho era, breaking Southampton hearts at the end of a thrilling EFL Cup final.
Wembley bore witness to a superb encounter as expectant United faced a Saints side looking to win just the second major trophy in their history, the first having come 41 years ago when the sides met in the FA Cup final.
Manolo Gabbiadini's brace had Southampton dreaming as Ibrahimovic and Jesse Lingard strikes were cancelled out, only for Ibrahimovic to head home three minutes time to clinch a hard-fought 3-2 win.
Europa League and FA Cup glory remain further possibilities this term, but Mourinho will know his players need to up their game moving forwards.
After Gabbiadini had seen an opening goal inexplicably ruled out, under-performing United showed their ruthless edge as Ibrahimovic fired home a free-kick before Lingard scored on a third straight Wembley appearance.
But it appeared a gut-punch rather than a decisive killer-blow. Gabbiadini gave Southampton hope with a close-range goal in first-half stoppage time, before sending the success-starved fans wild with an outstanding leveller.
Oriol Romeu crashed a header off the post shortly after avoiding a second yellow card, but it was not to be for Southampton.
Ibrahimovic's 26th goal of the season saw Mourinho become the first United manager to win a major trophy in his debut season, and earned the Portuguese a fourth League Cup triumph - a joint record with Brian Clough and Sir Alex Ferguson.
Few would have known United were the side making a record-equalling 49th trip to Wembley as Saints flew out the blocks.
Dusan Tadic and James Ward-Prowse proved a headache for United's rattled backline, with Nathan Redmond ending a mazy run with an attempt that deflected wide for a corner.
That start should have brought with it a goal in the 11th minute. Southampton's success-starved fans erupted as Gabbiadini turned home hard-working Cedric's cross from the right. Inexplicably, though, the assistant raised his flag for offside, despite the Italian being clearly on and Ryan Bertrand not interfering with play.
Saints soon had further reason to feel aggrieved at Stuart Burt's decision.
Romeu was booked for a lunge on Ander Herrera, giving Ibrahimovic a chance from 30 yards. It was an opportunity the in-form veteran took with aplomb, firing home a stunning free-kick and wheeling off towards his fans in celebration.
Saints' wall and goalkeeper Fraser Forster will feel they should have done better with the 19th-minute strike, which Puel's men busily went about cancelling out.
Ward-Prowse and Tadic forced the returning David de Gea into action from the edge of the box in quick succession.
United were not attacking with the same regularity, but unlike Saints made their threat count.
Marcos Rojo was allowed through to lay off to Lingard just inside the box, with Southampton's lack of pressure giving the attacking midfielder time to calmly side-foot past Forster.
But it was not a fatal strike after Saints collected themselves. In first-time stoppage time, Ward-Prowse's fine right-wing cross was met by a smart Gabbiadini touch, turning the ball past De Gea and turning to the assistant celebrating.
Michael Carrick replaced Juan Mata for a second period Southampton started brightly, with Redmond seeing an exquisite volley kept out by De Gea.
There was no let-up from Puel's men. Steven Davis beat Anthony Martial to a header and Gabbiadini swivelled expertly, firing through a crowd into the bottom corner in front of the Saints fans.
It was a moment of utter joy for half of Wembley - and one Ibrahimovic could have soon rendered worthless, only for Forster to recover from his poor clearance to smother.
Herrera claimed compatriot Romeu should have received a second booking after being clattered, but the appeals ere ignored, with the defensive midfielder soon leaping above Paul Pogba to power a header off a post.
United attempted to make the most of that let-off. A superb challenge from Maya Yoshida prevented Lingard from getting a shot away, before the unmarked winger wasted a glorious 76th-minute chance.
Redmond saw an attempt deflect wide as Saints pushed for a winner, although substitute Marcus Rashford came close to grabbing one at the other end by forcing Forster into a near-post stop.
It was a frantic conclusion and, having blocked a Stephens corner at the other end, Ibrahimovic secured the win.
Unmarked from six yards, he powered home Herrera's cross to secure a memorable win and send United fans wild.
Source: PA
