Watford - Manchester United collapsed to a humiliating 2-0 defeat against Premier League bottom side Watford on Sunday after a David de Gea howler, bringing their recent revival to a shuddering halt.
Not even the returning Paul Pogba, on as a second-half substitute, could save his misfiring team, who again struggled to impose themselves against one of the league's lesser lights.
The key moment in the match came in the 50th minute when De Gea somehow allowed a tame, spinning effort from Ismaila Sarr to creep through his hands and in at the near post.
Watford doubled their lead four minutes later when Troy Deeney fired home from the penalty spot after the otherwise impressive Aaron Wan-Bissaka brought down Sarr with a misjudged sliding tackle.
Nigel Pearson coaxed a battling performance from Watford in his first home game in charge and they deservedly won just their second league match of the season to give themselves hope of survival.
But for United it was another story of failing to make the most of their domination of possession.
Under Solskjaer, they have won 73 percent of the Premier League games in which they have had less possession than their opponents, compared to just 36 percent when they have enjoyed more.
"We were sloppy and gave the ball away numerous times, especially in the first half," United defender Harry Maguire told Sky Sports.
"I felt in the first half the game was there to be won. We should have scored in the first half. We have to be better against these so-called lower opposition sides who have a deep block."
There was no hint of the drama to come in a largely uneventful first half.
Anthony Martial scuffed a shot wide as United, backed by vocal away support, enjoyed the bulk of early possession while Watford looked a threat when they came forward.
The home side had the ball in the net, but the goal was ruled out for a foul on De Gea.
United continued to probe, looking for openings against an organised Watford team but struggled to find the attacking threat they had showed in recent wins against Tottenham and Manchester City.
They looked certain to take the lead in the 34th minute Jesse Lingard was clean through on goal but the midfielder's chip landed on the roof of Ben Foster's net.
Towards the end of the first half Watford enjoyed a sustained spell of possession but the teams went in at 0-0.
The game slipped from United's grasp early in the second half.
Will Hughes sent a free kick into the area and the ball fell to Sarr, who did not hit it cleanly but somehow the ball wriggled through De Gea's gloves.
United did not properly recover before Wan-Bissaka's foul enabled Deeney to make it 2-0 from the penalty spot.
Solskjaer threw on Mason Greenwood, Pogba and Juan Mata in a desperate search for some inspiration.
Ben Foster denied Pogba and Marcus Rashford late on as Watford claimed a first home win of the season to move level with Norwich City in 19th on 12 points - still six points from safety.
United sit eighth with 25 points after a first defeat in seven league matches.