Watford moved four points clear of the bottom three as a 4-1 win over 10-man Manchester United gave Claudio Ranieri a first home win as head coach.
It looked like it might not be their day as Ismaila Sarr was twice denied when Watford won an early penalty. His first first spot-kick was converted on the rebound by Kiko Femenia but a retake was awarded due to encroachment, with David De Gea diving to his left a second time to thwart the Senegalese.
But Watford took a 28th-minute lead as Joshua King turned in an Emmanuel Dennis cutback from the left.
Sarr made it 2-0 on 44 minutes with a brilliant finish after being teed up by Femenia.
Donny van de Beek, one of two half-time changes, took only four minutes to pull a goal back as he tapped in after Cristiano Ronaldo headed Jadon Sancho’s ball back across goal.
But the visitors’ hopes of a fightback were hit when Harry Maguire was shown a second yellow card for a challenge on Tom Cleverley.
Ronaldo was brilliantly denied an equaliser by Ben Foster before stoppage-time strikes by substitute Joao Pedro and Dennis sealed a Watford victory.
Man Utd drop to seventh place with 17 points, 12 behind leaders Chelsea and six off fourth-placed West Ham United after 12 matches.
They are four points ahead of 16th-placed Watford.
Watford: 28 Nov v Leicester (A)
Man Utd: 28 Nov v Chelsea (A)
Referee: Jonathan Moss Assistants: Marc Perry, Timothy Wood. Fourth official: Dean Whitestone. VAR: David Coote. Assistant VAR: Nick Hopton.