Alfred N'Diaye scored on his Hull City debut as Liverpool's terrible start to 2017 continued with a fourth defeat in five league and cup games.
Senegal forward N'Diaye, signed on loan from Villarreal, tapped home unmarked after Simon Mignolet dropped the ball at his feet.
Despite striker Sadio Mane's first start since 2 January, Liverpool failed to force a single save in the first half and were poor throughout.
Jordan Henderson was denied by Eldin Jakupovic but Hull, who have won all four home games under Marco Silva, sealed victory when Oumar Niasse, on loan from Everton, kept his composure after the Reds defence had been carved open.
Senegal forward N'Diaye, signed on loan from Villarreal, tapped home unmarked after Simon Mignolet dropped the ball at his feet.
Despite striker Sadio Mane's first start since 2 January, Liverpool failed to force a single save in the first half and were poor throughout.
Jordan Henderson was denied by Eldin Jakupovic but Hull, who have won all four home games under Marco Silva, sealed victory when Oumar Niasse, on loan from Everton, kept his composure after the Reds defence had been carved open.