Harry Maguire was sent off as Manchester United suffered their fifth defeat in seven Premier League games, a humbling 4-1 setback at Watford. First-half goals from Joshua King and Ismaila Sarr, who had an earlier penalty saved, piled pressure on struggling United boss Ole Gunnar Solskjaer at Vicarage Road.

Substitute Donny van de Beek pulled one back for United, who had captain Maguire dismissed for two bookable offenses.

But Claudio Ranieri's home team made sure with stoppage-time strikes from Joao Pedro and Emmanuel Dennis, earning a second win in seven matches to move four points clear of the relegation zone.

Watford were handed a great opportunity to take the lead in the sixth minute; Jon Moss pointed to the spot after Nemanja Matic's reckless slice at the ball culminated in Scott McTominay bundling over King.

Kiko Femenia slammed home the rebound after Sarr's penalty was saved, but the goal was disallowed for encroachment in the box, and the spot-kick ordered to be retaken, with David de Gea coming to the rescue once again.

But the United goalkeeper was helpless as the hosts took the lead in the 28th minute; King slotting home against his former club from Dennis' cutback.

Watford doubled their advantage just before the break; an unmarked Sarr taking a touch before drilling past De Gea from a tight angle.

Solskjaer introduced Van de Beek at the break, and the former Ajax midfielder immediately responded by heading home within five minutes of his introduction.

Foster then did brilliantly to deny Cristiano Ronaldo as the visitors turned up the pressure.

They continued to threaten after Maguire received a second yellow card for a rash challenge on Tom Cleverley in the 70th minute.

But their hopes were dashed as Watford struck twice in stoppage time; Pedro and Dennis drilling low shots past De Gea from a tight angle.