First-half goals from Alejandro Garnacho and Kobbie Mainoo proved the difference on what was a frustrating afternoon in the capital.
City dominated the second half with Erling Haaland hitting the bar and Kyle Walker denied by a stunning save from Andre Onana.
Substitute Jeremy Doku, who made a superb impact, then deservedly struck six minutes from time to set up a grandstand finish.
But United held on to claim the prize and deny Pep Guardiola’s men what would have been an historic back-to-back Double.
What happened
City came into the game seeking to make more history, United to try and secure a tangible reward to a disappointing season.
If anything, the pre-match atmosphere and build up was even more loud and passionate than 12 months ago as these two age old rivals locked horns on the biggest stage once again.
There may have been no 12 second goal drama this time around, unlike Ilkay Gundogan’s stunning opener in 2023, but just as 12 months ago there was a frantic action-packed start.
First Kyle Walker needed to be aware to Erling Haaland was sent flying in the box through a challenge by Lisandro Martinez but referee Andrew Madley adjudged no foul with VAR upholding that view.
It was a crackling start with both sides seeking to land an early psychological blow.
At the other end, City keeper Stefan Ortega Moreno needed to be alert to firmly grasp a powerful Alejandro Garnacho shot from just outside the box.
There was then a scare in the City box on 21 minutes as Stones made a vital block on Scott McTominay as he sought to capitalise on a loose pass before Mateo Kovacic completed the rescue mission as he cleared from Fernandes just in the nick of time.
The Croatian popped up almost immediately at the opposite end of the field drinking in an inviting ball from the right byline into the heart of the United box only for Kobbie Mainoo to clear.
But it was United who made the opening breakthrough on the half hour through Garnacho after a mix up between Josko Gvardiol and Ortega Moreno.
As United’s Argentine teenager chased down a long pass, Gvardiol attempted to head back but with Ortega Moreno coming out to the edge of his box, the ball instead popped up invitingly for Garnacho to fire into an unguarded net.
United then had the ball in the net again seven minutes later as Rashford met Garnacho’s cross but the flag had gone up for offside.
However, United did strike again to double their lead a minute later through the impressive Mainoo.
A long raking Rashford ball picked out the advancing Garnacho, on the right flank, he cut the ball back to Fernandes who delivered a delicate, disguised pass to the waiting Mainoo who side footed past Ortega Moreno from 12 yards.
City sought to summon up an immediate response after the restart with Manuel Akanji and Jeremy Doku both brought on in place of Nathan Ake and Mateo Kovacic.
There was a notable step up in City’s urgency and intensity and a superb Doku through ball on 54 minutes was inches away from finding the advancing Foden as he powered into the box.
A minute later City came even closer, more Doku brilliance picking out Erling Haaland in the middle of box.
The striker let fly with the sweetest of strikes but saw the effort cannon back off the underside of the bar.
City the made another switch, Julian Alvarez being ushered on in place of Kevin De Bruyne just shy of the hour.
The pressure was now all from City and it needed a stupendous save from Andre Onana to deny Kyle Walker when the skipper let fly from 25 yards.
Alvarez then blazed over from 18 yards after another inviting opportunity opened up inside the United box.
If anything, the Argentine then spurned an even better chance on 65 minutes as a superb Phil Foden assist put him clear in the box only for the striker to direct his effort wide of the target.
United gave a reminder of their threat with Garnacho forcing Ortega Moreno into another low block to deny his breakaway shot.
But one felt a goal had to come and it finally arrived on 87 minutes from that man Doku.
He wrestled his way free after cutting in from the edge of the box before letting fly and beating Onana at the near post.
It set up a grandstand finish with seven added minutes of time to play.
But despite knocking on the door we couldn’t find a way through.
Teams
CITY XI: Ortega Moreno, Walker (C), Stones, Ake (Akanji 45), Gvardiol, Rodrigo, Kovacic (Doku 45), De Bruyne (Alvarez 57), Bernardo, Foden, Haaland
Subs: Carson, Dias, Grealish, Alvarez, Nunes, Bobb, Lewis
UNITED XI: Onana, Wan-Bissaka, Varane, Martinez (Evans 74), Dalot, Amrabat, Mainoo, McTominay (Lindelof 92), Fernandes (C), Rashford (Hojlund 74), Garnacho (Mount 92).
Subs: Bayindir, Eriksen, Diallo, Kambwala, Antony.
What it means
No FA Cup then – but still a season to remember.
A haul of Premier League, UEFA Super Cup and FIFA Club World Cup is something we will all remember for a long time once the immediate disappointment of today subsides.
Pep reaction
Guardiola told the BBC: “We’ve had a fantastic season. We lost the game, congratulations to United.
“It was a tight game and after we conceded a goal and second half we had the chances.
“It changed our pace up front and overall we made a good personality considering the final. Congratulations to United.”
What’s next
It’s all about rest and recuperation - at least for a week or two - before the rigours of both EURO 2024 and the Copa America finals swing into view.
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