Corry Evans' early goal and Robert Koren's late effort secured victory 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 whilst Hull 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."
Source: PA
Source: PA