After the highs of big wins in big games, Nigel Pearson condemned Manchester United to their worst defeat of the season in his first home game in charge of Watford.
A five-minute spell at the start of the second half involved a catastrophic blunder from David de Gea before Aaron Wan-Bissaka gave Troy Deeney the opportunity to score from the penalty spot. It was a few moments of madness from a United side that was woeful throughout.
Paul Pogba made his long-awaited return from injury for United and though he was probably the side's best player, he couldn't help to turn things around.
Pearson's start at Watford has been encouraging. They were good against Liverpool last week but fell foul to the magic of Mo Salah and now they have outplayed United.
Solskjaer's United have had some impressive wins and performances this season but their record stands at just six wins from 18 games. It's not the kind of form that can be justified by claims of a 'long-term project' or a 'vision'.
Story of the game
That Watford's 50th-minute goal was the first shot on target of this match told the story of the first half. United were playing their seventh game of December, a month which has been as up and down as the rest of their season. Their sloppiness and lethargy showed as much.
Scott McTominay alone lost possession three times in the opening 15 minutes. Lee Mason's whistle saved the blushes of David de Gea, at least for a while. The Spaniard, for the second consecutive week, had seen the ball knocked out of his hands from a corner. Unlike at home to Everton last week, this was as soft as they come. Watford, though most of the fans didn't know it, should have been in front.
And yet, despite their uninspiring play, United too should have had a goal before the end of the half. Fed through beautifully by Martial, Lingard had plenty of time to think as he approached Foster one-on-one. He chipped it, or at least he tried to lob Foster. The Watford goalkeeper is 6ft 3in.
It was exactly one year on from Lingard's last goal in the league for United. This was his 28th appearance since that game, when United cruised to a 5-1 win in Solskjaer's first game in charge.
The United fans bemoaned Lingard's missed chance during half-time but four minutes after the restart, De Gea would provide a moment more inexplicable than any other for the Reds this season. Ismail Sarr volleyed a loose ball from a free-kick. It bounced, came back off the turf and went right through the hands of an under-performing De Gea. It was his third mistake of the week. Since the start of the last season, no Premier League player has made as many errors directly leading to a goal than De Gea.
If Ole Gunnar Solskjaer was left scratching his head at his goalkeeper's match-defining error, he would continue when Wan-Bissaka gave away a penalty three minutes later. It was a decision made easy for referee Mason and Wan-Bissaka was so blatantly late. It was one of his trademark tackles but this time it was ill-timed and very costly. Troy Deeney converted, as he has done from the penalty spot on four occasions at home against United now.
United tried to change things. 18-year-old Greenwood arrived on the pitch. Then Paul Pogba made his return from injury, accompanied with a pat on the back from a desperate Solskjaer. He was pretty lively, and probably United's best player.
Greenwood headed over. Martial couldn't quite finish off a sensational mazy run. Then Greenwood had to be inventive to try a lob over Foster. United threw everything at it, just as they've had to do when they've embarrassed themselves at Sheffield United or at home to Aston Villa.
Martial clipped a ball over the top for Rashford. In tight space, he chested it down, turned and fired with his left foot into Foster's chest. It was a difficult chance and it was one of those days. Martial created two chances with great footwork but both his efforts were saved. Why United can't produce moments like these before they go two goals down to the league's worst side will have to be explained by Solskjaer.
He's effected much positive change on United in his year in charge. And yet this is the ninth time this season that they've dropped points in relatively easy fixtures. They've now taken only five points, from a possible 30, in games against Wolves, Palace, Southampton, West Ham, Newcastle, Bournemouth, Sheffield United, Aston Villa and Watford.