Watford earned a first-ever Premier League point at Old Trafford with a goalless draw that dents Manchester United's hopes of a top-four finish.
Man Utd had 67 per cent possession and 22 shots but could not find a way past a Watford side who have kept three clean sheets in six matches under Roy Hodgson.
Cristiano Ronaldo hit a post five minutes in before Bruno Fernandes had two chances, being denied by a superb Ben Foster save before heading over Ronaldo's cross.
In the second half, Anthony Elanga shot wide after brilliant build-up play including a Paul Pogba flick, while Ronaldo had a shot blocked.
Ismaila Sarr fired just over as Watford nearly snatched a winner.
The point extends Man Utd's unbeaten run to eight matches and keeps them fourth on 47 points, two above Arsenal who have three matches in hand.
Watford remain 19th on 19 points, three from safety, but have played more matches than both Burnley and Everton directly above them.
Man Utd: 6 Mar v Man City (A)
Watford: 6 Mar v Arsenal (H)
Referee: Kevin Friend. Assistants: Adrian Holmes, Simon Beck. Fourth official: Dean Whitestone. VAR: Lee Mason. Assistant VAR: Timothy Wood.