Watford's challenge for the Championship's second automatic promotion spot behind Cardiff has faltered of late but, having won only one of their past five games, they picked up three points courtesy of Troy Deeney's fine first-half strike from 20 yards. It was no more than they deserved for a calm, controlled performance against opponents who, had they won, would have gone a long way towards securing automatic promotion themselves.
"A lot of brains and a lot of passion went into that performance and we got the reward," Gianfranco Zola said. "If we had lost, Hull would have gone seven points clear and been very difficult to catch but this team has never let me down in important games. I am very pleased and proud."
The first good chance was created by Watford, with the Swiss midfielder Almen Abdi exchanging passes with Deeney and bursting past James Chester into the Hull penalty area before thumping his shot wide.
The simplicity with which their defence had been penetrated seemed to unnerve Hull. Their five-man midfield dropped noticeably deeper and Watford, given space to play, began to settle into an effective passing rhythm.
The subdued murmuring of the crowd confirmed Watford's control was growing and five minutes before half-time they made their superiority pay when Matej Vydra cushioned the ball nicely for Deeney to shoot powerfully beyond David Stockdale.
Hull almost hit back before the interval, when Watford's 19-year-old goalkeeper, Jonathan Bond, saved George Boyd's close-range shot with his legs, and the teenager continued to impress after half-time. Having got a strong enough hand on Jay Simpson's powerful low shot to deflect the ball for a corner, he also saved competently from Robbie Brady and, more spectacularly from Robert Koren, but Hull found the pressure hard to sustain.
They were also in danger of being picked off on the break, as they nearly were shortly after the hour when Vydra's neat pass resulted in Deeney stinging Stockdale's hands from an angle.
Steve Bruce made a double substitution, switching personnel in midfield and taking off Gedo to push Boyd up front, but his side continued to find it hard to create clear-cut opportunities.
Eventually he threw on another striker in Nick Proschwitz but the Watford backline, superbly marshalled by Marco Cassetti and Joel Ekstrand, remained unflustered.
"I thought it was two very evenly matched teams and a fair result would have been a draw but one thing we have done all season is bounce back," the Hull manager said. "We're still in second and it's still in our hands."