Barry Robson scored a brilliant late winner as Middlesbrough kept up the pressure on leaders Southampton.
Robson fired an unstoppable 30-yard drive past Peter Gulacsi to end Hull's run of four straight league wins.
Hull had been the more impressive side for much of the game with Matty Fryatt heading wide before Aaron Mclean's shot was parried away by Jason Steele.
Hull improved and Gulacsi had to react sharply to save from Faris Haroun before Robson's late strike.
Only two places separated the teams in the table before the match, with the third-placed hosts, in particular, looking to keep pace with the top two.
It was Boro who had the better of the opening exchanges as Joe Bennett and Haroun combined to cause the visitors problems down the left.
Despite the hosts enjoying the majority of possession, the Tigers created the game's first chance as Fryatt missed a presentable headed chance.
Nick Barmby's side showed plenty of adventure, with Boro goalkeeper Jason Steele having to be at his sharpest to turn Andy Dawson's effort around the post.
Chances were proving increasingly few and far between in the second half until Hull midfielder Paul McKenna drove horribly wide after neat work from Robert Koren.
The miss was to prove costly as Robson snatched the three points with an unforgettable strike.
Middlesbrough manager Tony Mowbray:
"It was a great strike. Barry's got that in his boots.
"He's been great today. He's played in three different positions and done well in all of them then pops up with a strike like that."
Hull City caretaker manager Nick Barmby:
"For me it was a cast-iron penalty [when Matthew Bates challenged Matty Fryatt]. I thought it was clear that he had been brought down.
"I was disappointed with the result. I thought we dominated most of the first half, we were comfortable and we had the better of the chances.
"After the break, Boro were better and had a bit more possession but they didn't create much."