Even in such an unpredictable season, few could have foreseen this result.

The Blades had just five points to show from their first 19 games – the worst haul in Premier League history – and had not beaten the Red Devils since 1993, with their previous Old Trafford victory coming in 1973.

Kean got them off the mark from a corner as Billy Sharp’s push on David De Gea went unpunished midway through a first half in which Anthony Martial saw an equaliser ruled out.

The ineffective hosts eventually clawed one back through Maguire’s header from a corner, but Solskjaer’s comeback kings faltered in embarrassing fashion.

Sheffield United capitalised on some atrocious defending and Burke saw his effort rifle in off Axel Tuanzebe, sealing just a fourth win of the season in all competitions for his side.

The home side’s first league loss since November 1 was a shock to the system on a night that started with Marcus Rashford firing low and just wide.

But it soon became clear that while they were dominating possession, they were passive with the ball against the compact Blades, whose veteran striker was denied by De Gea when they got a first sniff.

The video assistant referee may have got involved for a potential offside against the 34-year-old, but there was a distinct lack of intervention in the 23rd minute.

Sharp appeared to barge into De Gea as the goalkeeper looked to deal with a John Fleck corner, but Bryan reached it instead and headed it in off the far post.

The shock opener left Solskjaer’s side in the all too familiar position of needing to come from behind, with Mason Greenwood seeing a snapshot saved before another effort was blocked.

Manchester United thought they had equalised when Martial slotted into an empty net, but Maguire was adjudged to have fouled goalkeeper Aaron Ramsdale when challenging for the ball.

The hosts raged but there was to be no reprieve and United created precious little before half-time.

Greenwood dragged wide after being put through by Bruno Fernandes early in the second half, but the visitors were having half-chances of their own.

David McGoldrick missed with an effort hit with the outside of his boot, then blazed over when one-on-one – unaware the offside flag would be raised.

Rashford fired a free-kick down the throat of Ramsdale as the hosts toiled, only for another set-piece to finally break the Blades’ resolve.

Alex Telles sent over a corner in the 64th minute and Phil Jagielka lost Maguire, who powered home a header and immediately raced back to the halfway line.

Fernandes tracked superbly to halt a break by the visitors, who were now having to deal with the presence of Edinson Cavani at the other end.

But just as Manchester United looked to be building momentum, the Blades caught them napping at the back.

Inexplicably bad defending from the hosts ended with John Lundstram cutting back for Burke, whose strike hit Tuanzebe – making his first league start of the season – and went in off the underside of the bar.

A Telles effort from distance looped just over Ramsdale’s goal as the hosts looked for another leveller, but the Blades dealt with their largely aimless attempts to find the net as Wilder’s side kept their cool and held on for a shock win.