United were heavily beaten by Everton at Goodison Park in one of the most embarrassing defeats in their history.
The Red Devils were in desperate need of a win to boost their hopes of finishing in the top four.
The match came five days after their Nou Camp thrashing in the Champions League where Barcelona, led by an inspired Lionel Messi, made easy work of United to go through to the next round.
Ole Gunnar Solskjaer was desperate for some form of reaction – but instead his side failed to turn up as Everton shipped four goals past a sorry Red Devils defence.
The Toffees beat United 4-0 after goals from Richarlison, Gylfi Sigurdsson, Lucas Digne and Theo Walcott.
Solskjaer’s side simply could not handle a rampant Everton, who have now beaten Chelsea, Arsenal and United in three consecutive home games without conceding a goal.
And in the process, the Old Trafford outfit have conceded the most goals they have ever let in during a Premier League season.
It happened shortly after half-time, when Digne produced an outrageous volley that flew past David de Gea after he could only punch a corner away.
The Frenchman’s strike was the 47th they had conceded this year in the league – the worst they have ever managed.
And matters turned ever sourer when former Arsenal star Walcott got on the scoresheet after being given the freedom of the pitch to slot past De Gea.
Solskjaer, forever the optimist, tried his best to pick up his squad in his post-match press conference, saying: “We’re way off where we want to be.
“When you lose in the league like we did here, everyone sees that we have a big job to do.
“This club has been down before, we’ve just got to pick ourselves up. It might not happen overnight, but it’s going to happen.
“You want to see the team express themselves. The goals were easy, we were sloppy on the ball. We cannot hide, we just have to step up and say we have to improve.
“We have to win all four games, then we might have a chance [of finishing in the top four]. It’s a big ask, but we can do it. We can’t just talk about it, we’ve got to do it.”