So, United move up to fifth in the table - unbeaten in their past 16 Premier League games. You can read a report of this game on the BBC Sport website. Many thanks for your company. Until next time.

Routine win for Manchester United, who move one point behind fourth-placed Manchester City.

Image source, Reuters

Antonio Valencia is booked for an untidy foul on Jose Holebas. That's the game's first yellow card.

Three additional minutes.

So where does this result leave United? They are currently fifth in the table - above Liverpool, who play Spurs later - and two points behind second-placed Tottenham. It's getting tight up there.

Henrikh Mkhitaryan will not finish this after all. He gets a pat on his back from his manager as Jesse Lingard is introduced for the final few moments.

There's a stoppage in play while Henrikh Mkhitaryan receives treatment as blood drips from his mouth following a collision. He's had another decent game and he wants to make sure he finishes it on the pitch. Mkhitaryan is quickly back on his feet.

Almost a third for United. Henrikh Mkhitaryan almost picks out Zlatan Ibrahimovic, unmarked and six yards out, but Younes Kaboul sticks out a leg and slices clear.

Anthony Martial's shift is over. A standing ovation for the young forward who is replaced by Marcus Rashford.

You have to feel sorry for Heurelho Gomes. He's made some terrific saves but the Watford keeper is going to end up on the losing side. Gomes gets his angles right again to deny Henrikh Mkhitaryan from inside the area.

Image source, Reuters

This has been another encouraging day for Jose Mourinho. His team's Premier League momentum continues to gather pace, while Liverpool and Arsenal struggle for consistency.

Applause rings out for goalscorer Juan Mata as he is replaced by Marouane Fellaini.

Image source, Reuters

Huge chance for Watford to score their first Old Trafford goal for 18 years. M'Baye Niang darts down the wing before delivering a lovely ball for Daryl Janmaat who fires wildly wide. Janmaat will not want to see that again.

Terry Butcher
Ex-England captain at Old Trafford for 5 live Sport

It looked an easy finish for Martial but that was because he chose to dwell on the ball and take his time. 

It was a swift United break and when Martial received the ball it looked easy enough to sweep it into the far corner. But he paused, the near post opened up and he slotted it home.

Martin Keown
Former Arsenal defender on Final Score

Martial has been pressurised by his manager and that's pleasing, because he's a great talent but he needs to start to show that in a United shirt. But now he's scored, and that will do his confidence a world of good.

Image source, Reuters

Should they hold on, this will be a significant win for United. They are not in Premier League action for another three weeks as they embark on a run of knockout games in the Europa League and FA Cup.

They could have their first major silverware of the season by the time they return to league action as they face Southampton in the EFL Cup final in two weeks.

Surely there's no coming back from this for Watford? United are set to extend their unbeaten Premier League run to 16 games.

United haven't hit the heights they scaled before the interval. Zlatan Ibrahimovic has just fired into the side netting but it's gone rather quiet at Old Trafford. Watford are still in this.

So close to a Watford equaliser! David de Gea produces a wonderful one-handed save to deny Mauro Zarate his first Watford goal after the visitors win a free-kick 20 yards out.