Ten Hag’s job is not safe, but Liverpool win will resonate for decades

aand in the next round, Mark Robins. Football has been attacked in recent years by states, oligarchs and private equity; the concentration of resources in a handful of clubs in a small number of Western European countries has destroyed the balance it once maintained; the potential of its soft power means football is under siege by regimes desperate to whitewash their image and secure their influence. But despite this, the sport has retained its mischievous sense of humor.

It was Robins who scored the winner for Manchester United against Nottingham Forest in 1990, saving Sir Alex Ferguson’s job and guiding them through the third round of the FA Cup to spark an exhaustingly dramatic campaign that culminated in the trophy. At the end of his fourth season in the role, it was Ferguson’s first success at Old Trafford, heralding 23 years of near-constant success.

Robins has an excellent record as a manager in the lower divisions. If Coventry win their Championship match they will be one point clear of the promotion play-offs and on Saturday they scored twice in stoppage time to beat Wolves in their own astonishing quarter-final. Robins has only faced United once before as manager, in the 2009/10 League Cup, when his Barnsley side lost 2-0. But every now and then football has an impeccable sense of timing: of course he should pop up again now, just as everyone is talking about Erik ten Hag enjoying his Robins moment.

In reality, what happened at Old Trafford on Sunday was far more dramatic than United’s victory over Forest 34 years ago. The latter match has been rather burnished by myth, a performance of grim challenge won with a header eleven minutes after the break. Only the context made it memorable. Sunday’s 4-3 win over Liverpool was a win for the ages, the kind of match that will stir the souls of United fans forever.

It felt like a game out of time. Players in the modern era don’t look as exhausted as they did on Sunday, dragging their limbs forward for another attack, socks around ankles, hair drenched in sweat, cramps gnawing at their calves. Modern teams don’t usually end up with an injured striker bouncing around as a centre-back. Trying to work out the United formation towards the end was impossible: Harry Maguire and Diogo Dalot were the only two defenders left, and yet Maguire kept popping up in the Liverpool box.

These were two groups of players who lived completely in the moment; no one kept anything in the tank for the upcoming internationals. There was no pleasure in penalty kicks, just brutal, end-to-end attacks. From United’s perspective, it was a victory in the best traditions of Matt Busby, rooted not in tactical scheme or clever counter-pressing, but in individual effort.

The Robins figure was unexpected – and therefore, given the nature of the FA Cup, entirely predictable. Amad Diallo was occasionally brilliant on loan to Sunderland last season, repeatedly darting in from the right flank, a waif, apparently too good for the Championship until he released his left foot: a weapon, despite his physical smallness, capable to hit balls with extraordinary speed and accuracy. His winner away at Birmingham was of such ridiculous quality that the only reasonable response was to laugh, the goal at Wigan not far away from.

Injury has hampered his return to United and, operating in his preferred role on the right, Alejandro Garnacho has been one of the few positives for United this season. Yet there was an element of frustration that Amad’s involvement this season was limited to four substitutes, with United unwilling to let him stay at Sunderland for another year.

It would be misleading to suggest that Sunday showed he can fit into a Ten Hag system, because what happened had little to do with structure. What Amad did show, however, was that when the game turns into chaos, he has a heart for the fight. It was he who won the ball back and, having taken Garnacho’s pass on the edge of the penalty area, had the means to shape his right foot. Connor Bradley checked – but Amad only uses his right foot when there is no option. He let the ball continue to roll, widening the angle and then, with Caoimhin Kelleher perhaps also momentarily deceived by the drop of the right shoulder, he blasted his shot just inside the far post. A wrong hit, some said, and it wasn’t the cleanest hit, but it was good enough; the cleverness of the finish lay in the way he had figured out a way to use his stronger foot.

Will it be enough to keep Ten Hag at work? Maybe maybe not. To some extent, it’s less about what United do next – although if they beat Manchester City in the final it would be difficult to dislodge him – than that, amid the kind of ecstasy that years of underachievement can make it seem. Worth it: United achieved a victory over their biggest rival that will be remembered for decades. In any case, Sunday ensured that if Ten Hag is fired in the summer, he will not go unnoticed.

• This is an excerpt from Soccer with Jonathan Wilson, the Guardian US’s weekly look at the game in Europe and beyond. Subscribe for free here. Do you have a question for Jonathan? Email footballwithjw@theguardian.com and he will provide the best answer in a future edition