In the lead up to this FA Cup final, Manchester City’s captain, Kyle Walker, had cited a notable shift in the sartorial habits of the city’s children as evidence of a power balance transformed.

“When I first came here [to Manchester] you saw a lot of United shirts and now you see a lot of kids wearing City shirts,” the defender told The Times. "We’re swinging the pendulum.”

For Kobbie Mainoo, though, ’twas ever thus, a boyhood United fan born and raised in Stockport - firm City territory - surrounded by classmates decked in blue.

And so how sweet this must have been, for the teenager in cup final triumph to steal the show, to outshine fellow Stockport lad Phil Foden, the Footballer of the Year, no less, and the rest of City’s champion midfield.

Mainoo started and finished the move that gave United the shock cushion of a 2-0 half-time lead, one of the best-crafted cup final strikes in recent memory and due reward for surely the finest 45 minutes of Erik ten Hag’s teetering reign. In pulling one back three minutes from the end of the 90, substitute Jeremy Doku even had the decency to ensure it will go down as the game's decisive goal.

The opener had been a mess of a thing, Josko Gvardiol and Stefan Ortega out of sync to leave a disbelieving Alejandro Garnacho a wide open goal, but in carving City apart from deep inside their own territory nine minutes later, United gave themselves visible belief in the prospect of toppling their rivals, who had taken the season’s league derbies by an aggregate 6-1.

Heading clear on the edge of his own box, Mainoo picked the ball back up off Bruno Fernandes and clipped it sweetly off the outside of his boot to Marcus Rashford on the left. The winger, whose own darts in behind had been repeatedly thwarted by the recovery pace of Walker, instead looked up and drilled a stunning switch out to Garnacho on the opposite flank. His cut-back looked prime for Fernandes to hit, but instead the Portuguese conjured a wonderful extra slip into the path of Mainoo. So clever was the pass that the midfielder might’ve been forgiven for being caught on his heels. Certainly, few others inside Wembley had seen it coming.

Cooly, though, Mainoo slid into the corner, his fourth goal of a season that, from a scoring perspective, has dealt exclusively in works of art.

If this is the end for Ten Hag, as reports on Friday suggested it would be regardless of result, then the trophy and denial of City's double-double is a fine parting gift. But long-term the Dutchman’s decision to accelerate Mainoo’s integration into United’s first team may well prove his most impactful act.

For so much of this brilliant breakthrough campaign - one that, lest we forget, began with a cruel preseason injury that threatened to stop it in its tracks - the 19-year-old has shone in spite of chaotic surrounds and underperforming peers.

Here, though, he was part of a cohesive, miserly midfield that shut City out almost entirely, Bernardo Silva’s long-range strike the favourites’s sole shot on target by half-time.

Paired with Sofyan Amrabat in a midfield-two that effectively played behind another midfield-four, Mainoo was outstanding in closing the spaces that Silva, Foden and Kevin de Bruyne so love to explore. De Bruyne’s withdrawal before the hour-mark was another small United win en route to a greater victory, the Belgian suffocated out of the showpiece.

Into the seventh minute of stoppage time, a roar from the United end told not of the final whistle but of Mainoo’s rightful confirmation as man-of-the-match.

So diligent was the youngster’s performance that, even taking his goal out of the equation, it ought to dampen any doubts as to his suitability for partnering Declan Rice in England’s midfield this summer.

There is no perfect candidate for the role in the lost, prime Kalvin Phillips mould, but of those available, few are markedly more disciplined and none as talented at relieving pressure with brave passes and turns. Here again, those virtues were on show against a side better than any Gareth Southgate’s will meet on the road to Berlin.