In a quite incredible game at Vicarage Road it was to be a late Michael Dawson own goal that eventually separated the sides, despite Watford formulating 22 shots but not a single one on target.
Watford dominate the contest from the outset as Yaboul strikes the woodwork
The Hornets showed their hand from the outset as they almost opened the scoring in the first four minutes. A Roberto Pereyra corner picked out Younes Kaboul with the central defender heading against the crossbar. Pereyra almost scored just moments later as his long range effort flew just wide.
Valon Behrami was next in line to try his luck, striking just wide from outside the box with still only ten minutes on the clock. Hull found themselves penned into their half and being forced to block Watford's shot after shot.
Ryan Mason eventually produced the first effort of note for the visitors as his left footed drive was saved by Heurelho Gomes. Hull were beginning to get a foothold in the game but it did not last long as Watford ramped up the pressure once more before the break, strike partners Troy Deeney and Odion Ighalo going closest with off-target efforts.
Pressure eventually pays off as Hull bad luck continues
Both sides exchanged opportunities in the opening minutes after the break, with Pereyra and Abel Hernandez both striking wide. A handful of poor challenges and bookings caused the flow of the play to be broken up but Watford still looked the most likely to score as numerous efforts flashed wide or over without really threatening David Marshall's goal.
Nordin Amrabat was looking particularly effective on the hosts' right wing and it was down that side they managed to formulate a breakthrough as Watford's dominance eventually paid off and the Hornets managed to inflict a vital sting on the Tigers.
Substitute Daryl Janmaat made headway down the flank and his flicked on cross by Pereyra deflected off Hull captain Michael Dawson and into the back of the net on 83 minutes. Hull had no answer and it was in fact Ighalo who went closest of anyone in the final minutes, though Dawson's own goal proved to be the vital moment in a fascinating contest.
The result meant Watford pushed up to seventh in the league and Hull remained with just one point in their last eight top flight matches. Although Mike Phelan has only recently been granted the Hull managerial position on a permanent basis, he will be starting to feel the pressure with his side rooted in the relegation zone. The Tigers are now without a win since the second week of the season, all of two months ago, only a week before Phelan won the Manager of the Month Award for August.