Corry Evans’s early goal and Robert Koren’s late effort secured the win for the Tigers before Martin Taylor headed home a Hornets consolation in stoppage time.
The home side’s play-off chances now look bleak as they slipped eight points adrift of the top six while the Tigers remain in contention being only five points shy.
Pearson said: “We played pretty well. We dealt with their threat well for the most part.
“The number of times they put the ball into the box it is difficult to cope with but the attitude and the spirit of the players shone through, so I was very pleased with how we went about it and on top of that I thought we played some good football on a difficult pitch at times.
“We’re disappointed not to keep a clean sheet having gone 2-0 up with time running out. It was a bit hairy towards the end but that’s what you get when you come to places like this.
“Their style of football is such that they’re going to have a lot of entries into the box and you’ve got to deal with and I thought the players coped with it very well.”
Hull made the perfect start to reinvigorate their promotion push when Liam Rosenior crossed for Evans to prod past Scott Loach for his second goal in Hull colours.
The goal gave Hull the confidence to probe the Watford backline, but for their possession, Loach was rarely tested.
It wasn’t until late that Hull doubled their advantage, Koren cashing in to nod home Tom Cairney’s centre after they had broken clear
On his side’s play-off hopes, he added: “We’ve got a lot to do. As you start to run out of games – to make up five points with six games left is a lot to do.
“But we’re going to give out our best to try and make inroads and see where it takes us.
“You’ve seen today by some of the results that spring up there are always going to be a few strange ones and what it does is keep the belief going that maybe we can sneak in there. But the bottom line is you’ve got to do it yourselves.
“We’ve got to win enough games and get enough points ourselves, so it’s not what other teams do necessarily, although we do need some help from other sides.”
Watford: Loach, Hodson, Taylor, Mariappa, Doyley, Eustace, Cowie, Buckley (Sordell 70), Jenkins (Deeney 86), Weimann (Whichelow 79), Graham. Unused substitutes: Gilmartin, Mingoia, Thompson, Drinkwater.
Hull City: Guzan, Rosenior, Hobbs, Gerrard, Dawson, Harper (Cairney 84), Chester, Koren, Evans, Fryatt (Garcia 66), Mclean (Simpson 56). Unused substitutes: Duke, Devitt, Amoo, Belaid.
Referee: D Phillips (West Sussex).
Hull man-of-the-match: Robert Koren.
Watford manager Malky Mackay felt his side were unlucky to not get something out of today’s npower Championship game at home to Hull, which they lost 2-1.
Mackay said: “I think we created enough chances, really good chances to win two games today and sometimes that’s the rub of the green. I felt the same at Coventry last week.
“Before today I asked the boys to make sure between now and the end of the season we try to win every game and compete and I think we did that.
“We had a poor goal as far as we’re concerned in the first minute or two but from that we stepped on, created two or three really good chances in the first half and continued that into the second half.
“The chances that we did create, their goalmouth was certainly living a charmed life.
“The [Hull] second goal could have been avoided. It was a poor piece of play from us to allow them to break on us.
“Even then, we scored a goal and we have a chance on their line in the last minute to go and get something out of the game, so I think the amount of chances we had - on another day they go in.”