Jose Mourinho has bemoaned Manchester United's inability to kill Watford off as the Hornets launched a late fightback in their Premier League meeting on Tuesday night.
The Red Devils surged into a three-goal lead at Vicarage Road thanks to a brace from Ashley Young and a clinical finish by Anthony Martial.
However, United were pegged back late in the second half through a penalty by Troy Deeney and an Abdoulaye Doucoure strike.
Jesse Lingard made sure of all three points for the visitors moments later for a final score of 4-2, but Mourinho was unhappy with his side's complacency in the second half.
"The second half should have been five or 6-0, it was easier to score than the first. We missed chances," Mourinho told reporters. "Out of nothing, they got a penalty for 3-1, then it was a different game. It was an easy match to win comfortably. At 3-2 the game is in the balance then Jesse Lingard had the initiative to kill the game.
"Both him and Ashley Young scored great goals. We missed 4-0 with some actions and Romelu Lukaku had an open goal, Paul Pogba had a free header too. They were full of confidence after, they had nothing to lose could play the way they do and got back into the game. We should be smoking cigars but then were in trouble."
Second-placed Man United, who now sit five points behind runaway leaders Manchester City, return to Premier League action on Saturday with a trip to Arsenal.