A spectacular own goal from Kyle Naughton gave Hull the lead midway through the first half, but a Billy Sharp strike saw the scores level at half-time. However, Hungarian Peter Halmosi became the match winner on 55 minutes, as he calmly sent the ball into the bottom corner from five yards.
The visitors had a chance early on as Brian Howard lofted a cross from the right onto the head of the rising Greg Halford, but the Sunderland loanee could only send the ball just wide from six yards.
Kamil Zayatte then came close for the home side as Halmosi whipped in left-footed corner on to the head of the defender, but his glancing effort from close range whistled just over the bar.
Caleb Folan was next to come close for the Tigers, but his close-range header from a Dean Marney corner flew just over the visitors' crossbar.
Hull took the lead in controversial circumstances on 24 minutes. While attempting to clear a looping cross from Nathan Doyle, Blades defender Naughton fired a header on to the underside of his own crossbar, with referee Peter Walton ruling that the ball had crossed the line before bouncing back out.
However, United were back on level terms within ten minutes as Halford sent in a curling cross from the right towards Lee Hendrie, who nodded the ball back across the box to Sharp, who made no mistake from five yards to register his sixth goal of the season.
Halmosi had his Hull side back in front ten minutes into the second half, as veteran Nick Barmby floated a cross from the right onto the left foot of the ex-Plymouth man, who neatly slotted the ball home from close range to bag his first ever goal for the Tigers.
Hull substitute Manucho had a decent chance midway through the second half as Barmby slipped him a neat through ball from the right.
However, the Manchester United loanee was beaten to the ball by keeper Paddy Kenny, who showed enough awareness to run out and snuff out the danger.