By Charlie Bennett

If this is to be Erik ten Hag’s last act as Manchester United manager, then he is going out with the biggest of bangs.

Bold, spirited and tactically astute, he outthought and his team outfought this great Manchester City side to win a 13th FA Cup with a shock 2-1 victory that - whether it saves his job or not - changes the perception around him.

United, who like to proclaim themselves as the world’s biggest club, don’t suit the underdogs tag. But after finishing 31 points behind the juggernauts across town in the league, they started as such, and Ten Hag responded by masterminding a fine win that gives him plenty of ammunition in the crunch talks he is set to have with his bosses.

It was built on the back of two 19-year-olds.

Kobbie Mainoo came of age on the biggest stage with a man-of-the-match performance that should not only cement his place in England’s Euros squad, but catapult him into the team, while his fellow goalscorer Alejandro Garnacho's blistering pace terrorised City’s defence.

At the back, Raphael Varane and Lisandro Martinez rekindled their successful centre-back partnership after an injury-hit campaign and kept United as defensively stable as it’s possible to be against a City team boasting such attacking riches – and Ten Hag was left to bask in the glory of a result that restores some of his reputation after a troubled season.

Asked about his future, he said: "I don’t know. The only thing I’m doing is preparing my team, developing my team. This is a project for me. When I came in I can say it was a mess. Now we are better. We are not where we want to be.”

Asked if the criticism of his team has been unfair, he said: "I think so. The team, me as well. It was not right.

"But we didn’t have the players. We have seen the same things, not always good football - definitely not - but we had to make compromises all the time and then you can’t play the football you want to play.”

Unfair or not, intense scrutiny has followed Ten Hag for months, so he can be forgiven for flipping a metaphorical middle finger to those who have doubted his ability to do to the job.

But when the giddiness dies down, he must confront the awkward question of where this United have been all season, as the owners pick the bones out of a largely joyless, arm-wrestle of a campaign that has brought little more than embarrassing defeats, a plethora of injuries and that leaking roof to Old Trafford.

On the eve of this match, strong rumours began circulating that Ten Hag’s P45 is in the post, but he can now point to a performance that suggests his plan has not totally failed yet.

Indeed, City boss Pep Guardiola was quick to highlight he had been outfoxed.

“My game plan was not good, the second half was much better in part because were more intense because we had nothing to lose,” he said.

“Erik is a lovely person and an extraordinary manager. Winning the FA Cup is important for them like last season it was for us." Sir Jim Ratcliffe, it appears, has a tricky decision to make.

The new Wembley cops its fair share of flak for providing a bad atmosphere, but it was built for matches like this.

United sat deep and soaked up the pressure City applied, before hitting them on the counter-attack, led by the mature Mainoo and executed by wingers Marcus Rashford and Garnacho.

The latter broke the deadlock by capitalising on the sort of defensive mistake normally seen in Sunday league, as Josko Gvardiol headed a bouncing ball over his goalkeeper’s head, for Garnacho to tap in.

But the second goal was excellent, with Rashford spreading the ball to Garnacho, who then cut-back for Fernandes, who in-turn flicked on to an open Mainoo to calmly side-foot home.

“It means absolutely everything,” Mainoo said.

“It's been a tough season with ups and downs. This is the only thing we’ve had to look forward to. Last year I was in the stands.”

This time, it was England manager Gareth Southgate watching from the stands – and like everyone else, he watched Mainoo run the show.

The 19-year-old will now join an England squad with its eyes on Euro 2024 glory, but who his club manager will be when he returns is uncertain.

So legend has it, it was winning a FA Cup after a troubled season that saved Sir Alex Ferguson’s job in 1990 – and the rest, incorporating those 13 league titles and two European Cups, is history.

Ten Hag can only hope history will repeat itself.