Hull went ahead after Jake Livermore’s shot from outside the area took a deflection off Liverpool defender Martin Skrtel and looped over goalkeeper Simon Mignolet in the 20th minute at the KC Stadium.
Steven Gerrard equalized seven minutes later with a well-placed free kick through a sudden hole in the wall created by Skrtel.
David Meyler put Hull ahead again in the 72nd with a left-footed shot and Skrtel finished a miserable afternoon for Liverpool with a spectacular own-goal header in the 87th.
Liverpool, which trails league leaders Arsenal by seven points, missed England forward Daniel Sturridge who is likely to be out for at least six weeks with an ankle injury.
Liverpool manager Brendan Rodgers had recalled Victor Moses and Raheem Sterling, the latter making his first start since Oct. 5, but they proved inadequate replacements for Sturridge.
For Hull, it was a memorable afternoon and a season’s best performance – just the boost required after last week’s defeat to lowly Crystal Palace.
The match quickly settled into a pattern of Liverpool going forward and Hull clearing its lines.
The Reds forced three corners in the first six minutes, but the hosts stood up well to Gerrard’s delivery.
There were hints that Hull was not going to be completely passive, though, with Yannick Sagbo and Livermore creating a promising counter-attack in the 14th minute only for Robert Koren to linger too long over a final ball.
Nevertheless, it was still a major surprise when Hull went ahead six minutes later.
Moses was culpable, giving the ball away to Ahmed Elmohamady when trying to attack from the back and bringing Livermore into the game.
He exchanged a quick one-two with Meyler, advanced on goal and saw his 20-yard strike loop past Mignolet via a heavy deflection off Skrtel for Livermore’s first goal of the season.
With 26 minutes gone Curtis Davies felled the advancing Jordan Henderson and offered Liverpool the most inviting of free kicks.
Luis Suarez appeared interested but Gerrard pulled rank and bent the ball brilliantly past Allan McGregor after Skrtel pulled away from the wall to create a gap.
The leveler settled Liverpool and both Gerrard and Suarez began to play with greater freedom as they probed Hull for further openings.
Yet they did not have a shot of note between them until the stroke of half time when Suarez hit an unusually tame effort from Sterling’s clever through ball.
Liverpool started the second period shakily with Moses and Sterling offering little cutting edge in support of Suarez.
Meyler grabbed the second, driving into the bottom corner after his initial strike was blocked by Kolo Toure.
With Liverpool throwing numbers forward, a third goal seemed inevitable and came when Tom Huddlestone’s shot looked to be heading well wide until Skrtel’s deflection.