On 75 minutes up stepped Kobbie Mainoo with the coolest of winners before the Stretford End to cause bedlam among home fans and wrest the bragging rights Manchester United’s way.

After a raid down the left Alexis Mac Allister’s weak clearance rolled to the midfielder who beat Dominik Szoboszlai to punch home a finish that bested Freddie Woodman to the Liverpool goalkeeper’s right.

After ceding a 2-0 half-time lead this ensured a league double over the visitors for a first time in a decade. Yet zoom out, and as United and Liverpool are not in the title race this meeting of England’s heavyweights was akin to two follicly-challenged men fighting over a comb.

Michael Carrick and his men will, of course, be far happier – as victory also confirmed what was all but a (mathematical) certainty: United are back in the Champions League next season and the interim manager has every chance of being offered the No 1 job.

He will not be content, though, with how United folded after the interval, allowing Arne Slot’s visitors to respond to Matheus Cunha and Benjamin Sesko’s first-half strikes with goals by Szoboszlai and Cody Gakpo. Each derived from errant United passes, from Amad Diallo for Szoboszlai’s, Senne Lammens’ for Gakpo’s equaliser.

United were as lively as against Brentford on Monday at the start, launching several raids down the right. These involved Bruno Fernandes, Diogo Dalot and Bryan Mbeumo, whose corner from the last of these presaged Cunha’s opener.

The right wingman delivered from his flank and the ball bounced to Cunha. A first effort came back via Ryan Gravenberch. This time, with his left boot, the shot caromed off Mac Allister and beat Woodman to the keeper’s left and home celebrations broke out.

Soon, there were more as United’s thrust shredded Liverpool. Again, from the right, Fernandes crossed for Sesko who was impeded and did not finish. Down to the turf went the No 9 who sprang back up as the attack continued. This time Luke Shaw, from the left, popped the ball over for the ever-threatening Fernandes. He flicked a header back, this was palmed by Woodman on to the centre-forward who, falling over once more, bundled in United’s second.

Two-nil up 14 minutes in was the visitors’ worst nightmare. Liverpool were unable to breach United territory. Slot’s 4-2-2-2 formation - fielded due to Alexander Isak’s absence – that positioned Florian Wirtz and Szoboszlai as the (false-ish) 9s was near-toothless. When Gakpo found room by the home D and shot this went wide but at least space had been found by the division’s fourth-placed side.

Liverpool’s issue was allowing too much of this to United. Fernandes missed a simple opening - for him - from a Mbeumo cross, cannoning the attempt wide, as he and the winger were unmarked.

Liverpool were ragged. Szoboszlai, supposedly their totem, and Wirtz misplaced passes, and the pace was too fast for all in white. They were aided by Darren England whose eyes seemed awry, as the referee missed “fouls” by Szoboszlai, then Mac Allister when he pulled Mbeumo down.

Slot was reduced to arm-flailing frustration after Jeremie Frimpong, in for the injured Mohamed Salah, was caught offside, the crime more blatant as this was during a soporific build-up rather than quick counter.

As the news filtered through of Sir Alex Ferguson being taken to hospital as a precautionary measure due to feeling unwell, the former manager, who is said to be out of harm’s way, would have been proud of United’s front-foot mode.

One of Cunha and Sesko should have netted a third as the interval neared. Then, in the period’s added time, Fernandes floated a corner over from the left: it amounted to nothing, unlike the 45 minutes, generally, for United.

For the second half Diallo replaced Sesko, the Ivorian hugged by Carrick as he headed on. Instantly the decision backfired. Near the centre circle the winger spilt the ball to Szoboszlai.

He skated forward, Harry Maguire backed off and kept doing so, the Hungarian slalomed to right of Lammens’ goal, then coolly rolled beyond the keeper into the left corner, Diogo Dalot perhaps unsighting the Belgian.

This was superb from Szoboszlai, calamitous from Diallo and Maguire. So what finer riposte than a fluid home move? It featured Casemiro spiralling ball in, Fernandes killing this, along the right, then pinging across, and Mbuemo’s backheel defeating Woodman, only the right post saving Liverpool.

Yet nothing saved Lammens when the usually reliable stopper dropped his clanger. Aiming for Casemiro he found Mac Allister lurking. The Argentinian tapped to Szoboszlai and as the hapless Lammens rushed out Gakpo was found and he made the score 2-2.

Lammens grimaced, Carrick was dumbfounded, and the visiting congregation partied. Liverpool were inferior in all but spirit: enough to draw level and stymie United who now had more of the contest coming at them.

Example: Szoboszlai swung in a free-kick, United’s rearguard slumbered and Lammens stabbed the ball off the line.

Now, though, came Mainoo’s clincher and United remain headed for a finish of third.