Super sub Harry Maguire’s stoppage-time header saved Manchester United’s blushes and potentially Erik ten Hag’s job as the Europa League clash with Porto ended in a thrilling 3-3 draw.

Four days after their 3-0 home humiliation at the hands of Tottenham, the Red Devils put criticism of the players and their under-fire manager to the side with an impressive start in Portugal.

Goals from Marcus Rashford and Rasmus Hojlund had United in control, only for Ten Hag’s men to lose their way and their defensive faculties as Pepe scored before Samu Omorodion’s brilliant brace.

Captain Bruno Fernandes was sent off for the second straight match as Ten Hag squirmed, only for Maguire to head home a Christian Eriksen corner in stoppage time to seal a point.

The Dutchman will be grateful to the towering centre-back after coming to the rescue in what always looked to be the toughest assignment in the new-look Europa League.

But the manner of the performance in Porto does little to help Ten Hag ahead of Sunday’s Premier League trip to Aston Villa and the October international break.

It was a crazy end to a match that had started so brilliantly from a United perspective.

With seven minutes on the clock, Rashford collected the ball wide on the left and darted towards the box, showing great footwork under pressure to cut between two players and hit a low snapshot that Diogo Costa let squirm past him.

United pushed for a quickfire second, with a slight defensive touch taking a tantalising Rashford cross wide before a panicked Porto clearance at a corner hit a team-mate and flew over their own goal.

The second Ten Hag’s men threatened arrived in the 20th minute.

Eriksen played wide to Rashford, who slipped in underlapping Hojlund to hit a first-time drive that Costa was unable to stop and Nehuen Perez could not prevent crossing the line.

The United striker, making his first start of the season, made a point of celebrating with David Binningsley, who was the main physio during his recovery from a hamstring injury sustained on their pre-season tour.

Costa denied Rashford as United pushed on, only for an all too familiar stumble.

Porto pulled one back in the 27th minute as Pepe caught Lisandro Martinez napping and nodded home after Andre Onana had impressively stopped Noussair Mazraoui scoring an own goal.

United looked dazed on the banks of the Douro and Samu beat Matthijs de Ligt to Joao Mario’s clipped cross, with his powerful close-range header flying past Onana and sparking wild celebrations.

Assistant Ruud van Nistelrooy was booked in the aftermath of the equaliser.

United eventually settled and Casemiro was stopped before Rashford ended a fine run with a poor blocked shot – his last moment of note before the presumably injured forward was replaced by Alejandro Garnacho at the break.

Ten Hag’s side made a stumbling start to the second half, with Onana having to save from Francisco Moura after being allowed in on goal.

It was a warning shot United failed to heed and in the 50th minute Porto punished them.

A quick pass and a poor defensive line meant Pepe was behind and onside, with Samu smartly beating De Ligt to meet a cut back with a rifled strike into the top corner.

United belatedly regained a modicum of composure and pushed to level, with Costa denying Mazraoui before Garnacho failed with the follow-up.

Onana got down well to stop Samu completing a hat-trick as the visitors became desperate with their play and their fans chanted “attack, attack, attack.”

A tough ask got harder when already booked Fernandes stretched and was adjudged to have caught Perez with a high boot, leading Tobias Stieler to dish out a second yellow card.

Costa tipped over a shot by Garnacho as play swung from end to end and United stared down the barrel of an embarrassing defeat.

But early in stoppage time substitute Maguire met an Eriksen corner with a powerful header that secured a last-gasp draw.