Matej Vydra scored his 19th Championship goal of the season as Watford came from behind to beat Bolton and move to within a point of the automatic promotion places.
The Hornets, who were beaten 2-0 by Bristol City in midweek, fell behind to Marvin Sordell's penalty following Daniel Pudil's foul on Sam Ricketts.
But Vydra equalised when he coolly stroked the ball home from 10 yards.
And Almen Abdi earned victory when he shot into the bottom corner.
Bolton, who slip to just two places and three points above the relegation zone, had started brightly enough and looked well set for at least a point when Sordell calmly found the bottom corner of the net from the spot.
But Watford had created the better chances up until then, notably when Troy Deeney was denied by the legs of away keeper Adam Bogdan.
On-loan Udinese striker Vydra showed great footwork and composure to run through Bolton's defence and level before the break after Cristian Battocchio had flicked the ball forward.
The hosts, top scorers in the Championship this season, chased a second goal and continued to have the upper hand in a scrappy second half.
Eventually the pressure told as Abdi gave them the lead from the edge of the area after a sustained spell of possession.
The Hornets dominated the closing stages and easily held on for victory.