Michael Dawson's first-half header was enough to down a lacklustre Reds, with Mario Balotelli and Raheem Sterling struggling to make an impact in attackHull City took an important step towards Premier League survival with a 1-0 win over Liverpool that leaves their opponents' chances of Champions League qualification in tatters.
As in their goalless draw at West Brom on Saturday, Liverpool's pleasing work on the ball was undermined by a lack of end product as Mario Balotelli and Raheem Sterling turned in abject performances in attack.
It meant Hull's breakthrough late in the first half, when Michael Dawson was afforded ample room to head home, proved decisive as Steve Bruce's men backed up Saturday's 2-0 win at Crystal Palace with another vital three-point haul.
They sit four points above the relegation zone with as many matches to go and three of those games will be played before a KC Stadium that roared euphorically at the full-time whistle.
A run of one win in five league games means Liverpool lie seven points behind fourth-placed Manchester United, with the odds stacked against them overturning the deficit.
Bruce named the same team that triumphed at Selhurst Park, while Joe Allen came into the Liverpool side for Steven Gerrard - the club captain not featuring in Brendan Rodgers' matchday squad.
Dame N'Doye was Hull's two-goal hero at the weekend and could have opened the scoring for the hosts after seven minutes, but his header from Robbie Brady's superb left-wing cross was too close to Liverpool goalkeeper Simon Mignolet.
A cleverly worked corner routine saw Philippe Coutinho test Mignolet's opposite number Steve Harper with a crisp half volley in the 19th minute, with Tom Huddlestone alert to clear the rebound to safety.
City went ahead when a 37th-minute corner reached Ahmed Elmohamady on the right. He hoisted the ball back into the box and, although three Hull players were in offside positions as the Liverpool defence pushed out, Dawson timed his run perfectly to plant a header past Mignolet.
Balotelli was enduring a familiarly lacklustre evening in Liverpool colours and failed to touch a low Glen Johnson cross into an unguarded net before the half-time whistle sounded.
Sterling found himself outmuscled when trying to convert Henderson's searching ball from the right, with the visitors failing to turn their dominance of possession into chances.
One arrived in the 63rd minute as Henderson met Coutinho's chipped pass with left-footed volley on the turn, although Harper was down brilliantly to turn behind.
Rodgers sent on Adam Lallana and Rickie Lambert for Jordon Ibe and Balotelli shortly afterwards - the enigmatic Italian departing to ironic cheers from the home faithful.
Harper's handling let him down behind Henderson's 71st-minute drive, but he was able to collect the rebound with no Liverpool forwards lurking.
They were no more incisive in the opposition box during the closing stages as Rodgers endured a second loss at the KC Stadium in as many seasons.