The hosts had several chances to double their lead in the second half, but Scott Arfield fired in the equaliser to earn his side a point late on.
The striker saw a similar effort fly past the post shortly afterwards before a couple of half-chances for the visitors came to nothing.
Burnley improved after half time with Michael Kightly and Ross Wallace going close before Watford somehow failed to double their lead from a corner, as Daniel Pudil, Gabriele Angella and Joel Ekstrand all had efforts blocked during a melee in front of goal.
With five minutes to go, Burnley finally got their equaliser as Arfield found the bottom corner from just outside the box to edge his side closer to promotion. body check tags ::