Erik ten Hag was skipping down the touchline in ungainly, awkward joy. A match to save Manchester United’s season, in his own description, may end up saving his job. It certainly ensured that Liverpool will not win the quadruple, that Jurgen Klopp’s reign will not end at Wembley in May’s FA Cup final and, as a result, that he will not face Pep Guardiola in England again.

But while United often delight in Liverpool’s misfortunes, the euphoria reflected an extraordinary end to an epic encounter. This was about United, about the manner of their rescue act and the improbability of it all. Amad Diallo’s lone United goal came three years ago. He has been a bit-part figure at best, but he emerged from the margins to come off the bench, deliver an extra-time winner and be sent off for his celebration. While Ten Hag danced, Amad removed his shirt, at a cost of a second caution, but the telling part was the lightning counterattack, Alejandro Garnacho releasing the Ivorian to slide his shot past Caoimhin Kelleher.

Finally, in a seven-goal affair of fluctuating fortunes and emotions, seven months into Liverpool’s astonishing season, someone had found a way of stopping them in a competition. United did it the long way, the hard way, the dramatic way. They mustered a rousing, rattling start, capped by Scott McTominay’s 10th-minute opener. They trailed twice but they came back on each occasion.

Amad was not the only surprise scorer. Not when their 88th-minute equaliser was doubly unlikely, in that it came from Antony and via a right foot he generally only uses for standing on. It was his first goal against anyone other than Newport County for 336 days. When Ten Hag required a saviour, he may have found one in his worst signing.

Marcus Rashford, meanwhile, had his own redemption tale. Having missed the chance to win it with the last kick of regulation time, shooting wastefully wide, his radar was better attuned in extra time when he latched on to McTominay’s pass to level.

For United, it was a show of spirit that they have only infrequently produced this season. It was a major scalp for a team who, two wins over Aston Villa apart, have rarely beaten the better sides. It was a sign Ten Hag could still motivate them, that they could still perform under pressure. For a manager whose first United victory was against Liverpool, 19 months ago, it was another way of exorcising the ghost of last season’s 7-0 hammering.

And it left Liverpool in a strange position: out of something. This was a match that had many of the hallmarks of their triumphs this season, yet it brought defeat. They are practised in the art of the comeback and staged a four-minute turnaround at the end of the first half. Their season has been notable for the success of Klopp’s signings, and Alexis Mac Allister scored as he and Wataru Endo excelled, despite the Japanese’s inability to stop the winner.

Substitutes have been a story of Liverpool’s season, Klopp conjuring goals and assists from the bench. He found another scorer from the ranks of his replacements. Harvey Elliott’s 105th-minute strike seemed to be an Old Trafford winner by a Liverpool fan.

Instead, that advantage was swept away as United, irrepressible and ultimately irresistibly, rebounded. The replacements to finally exert a decisive impact were Antony and then Amad, two of a raft of attacking changes by Ten Hag. Perhaps Liverpool’s Herculean efforts of late took a toll as they were unable to hold on to leads. Certainly they have been able to fight on four fronts even without a watertight defence. On a day when Kelleher made several saves, he still conceded four. As the shot count for the two teams passed half a century, he and Andre Onana both showed a defiance.

And while a gulf can sometimes seem to separate Liverpool and United, there were two tales of resolve and resourcefulness to the responses. United struck first, subjecting Liverpool to a dose of their own medicine with a swift start. Kelleher had already denied Rashford when he blocked a Garnacho shot, only for McTominay to poke in the rebound.

Liverpool assumed control. Endo had a goal disallowed then Mac Allister’s shot was deflected in off Kobbie Mainoo. He was teed up by Darwin Nunez but the instigator of the move was Jarell Quansah, surging out of defence in the manner of the injured Joel Matip. Then Mohamed Salah fired in his ninth goal in six games against United after Onana parried Nunez’s shot.

But a different, less prolific, left-footed right winger had his say, Antony squeezing in a shot on the turn. Then it was Elliott, fresh from hitting the post with an audacious shot from an acute angle, whose effort deflected in off Christian Eriksen.

Yet when Ten Hag felt beleaguered, his side showed the traits of Sir Alex Ferguson. They never gave up. They saw their season coming to a death and gave it new life. There was Rashford, then there was Diallo. Behind after 112 minutes, ahead after 120, United turned the game around; perhaps a campaign and a reign too. Because there were four goals for them. And now there won’t be four trophies for Liverpool.