Tottenham’s 10 men held on to claim a point at Vicarage Road as their winless Premier League run extended to four games.
Heung-min Son’s strike cancelled out Christian Kabasele’s opener for Watford before Spurs had defender Davinson Sanchez sent off for fouling Richarlison early in the second half.
Spurs started brightly but they fell behind in the 13th minute after failing to defend a Tom Cleverley corner, with Kabasele leaping above Harry Kane to direct his header into the net.
Although Tottenham continued to look uncomfortable defending balls into the penalty area, their equaliser, also against the run of play, arrived 12 minutes later.
Watford’s appeals for a foul on Richarlison went unheeded and the visitors counter-attacked down the right flank as Christian Eriksen’s low cross was tucked away by Son.
The sides remained level in terms of goals, but Spurs were reduced in personnel after the Colombian centre-half’s elbow on Richarlison earned him a straight red card.
And the 10 men were fortunate to remain level when Abdoulaye Doucoure’s 25-yard drive crashed against the inside of a post with Hugo Lloris rooted to the spot.
But Tottenham’s back line held firm and – despite a last-gasp penalty appeal when Eric Dier appeared to handle Richarlison’s cross – deservedly secured the draw.
Tottenham: Lloris; Trippier, Sanchez, Vertonghen, Davies; Dier, Dembele; Son (Lamela 77), Alli (Winks 86), Eriksen (Sissoko 64); Kane.