Steve Bruce felt his side were more convincing winners than the 2-1 scoreline suggested after his Hull side strengthened their pre-Christmas play-off push and ended Watford's seven-game unbeaten run.
The Tigers were by far the better team in the first half and took the lead when David Meyler headed home after a Corry Evans shot had rebounded off the crossbar.
Watford improved after the break and Almen Abdi hit the post before the Tigers doubled their lead through Robbie Brady's 25-yard free-kick.
Nathaniel Chalobah could have set up an exciting finale had his shot not been cleared off the line, although the Hornets did score in injury time when Troy Deeney netted his seventh goal in six games.
Bruce said: "Watford in the second half were better but the first half I can't really remember my goalkeeper having a touch of the ball and we've had two chances in the first three minutes which we've missed.
"But we knew Gianfranco's (Zola) team would be different in the second half, they're on a great run of form but I think we were worthy winners. We could have been and should have been out of sight."
Like his opposite number, Zola felt his side were below par in the opening period.
Asked whether it was the result or performance that disappointed him the most, the Hornets head coach replied: "I think it was a bit of both, probably I'm more disappointed in the performance in the first half.
"The second half was better, the approach was better, we created more chances, we could even have drawn the game in the end but you can't give away 45 minutes like we did."