Manchester City restored their five-point lead over Liverpool at the top of the Premier League as a goal in each half by Leroy Sane and Riyad Mahrez secured a 2-1 win at Watford.
Ben Foster kept the Hornets in the match midway through the first half with a brilliant triple save from Mahrez twice and David Silva.
But the leaders made the breakthrough in the 40th minute when Leroy Sane chested Mahrez's inviting cross past Foster.
The Algerian winger doubled City's lead 11 minutes later when he swept in Gabriel Jesus’s left-wing cross.
Abdoulaye Doucoure gave Watford hope when he scrambled the ball in at the third attempt late on, but the champions saw out their 14th consecutive PL away victory.
City move on to 41 points, while the Hornets drop to 11th on 20.
Watford: 10 Dec v Everton (A)
Man City: 8 Dec v Chelsea (A)