Emmanuel Dennis came on as a substitue in Watford’s 2-0 loss at Anfield which compounded their woes and increased the likelyhood of Championship football next season.
Liverpool climbed to the top of the table as goals from Diogo Jota and Fabinho secured a vital win, the Reds’ 10th consecutive Premier League victory.
Watford had a golden chance to take the lead as Juraj Kucka ran through on goal in the 22nd minute, but Alisson denied the Slovak and 34 seconds later Liverpool scored at the other end.
Joe Gomez, deputising at right-back, delivered a cross that Trent Alexander-Arnold would have been proud of and Jota arrived ahead of goalkeeper Ben Foster to head in.
Liverpool had another big scare in the second half as Joao Pedro fired wide from 12 yards.
But they wrapped up the points in the 89th minute when Kucka hauled down Jota at a corner and substitute Fabinho converted the resulting penalty.
Liverpool move two points ahead of Manchester City, who visit Burnley at 15:00 BST.
Watford remain 18th, three points from safety having played three more matches than 17th-placed Everton.
There was no place even on the substitute bench for Nigeria’s trio of Troost-Ekong, Oghenekaro Etebo and Samuel Kalu.