Liverpool - Manchester United captain Wayne Rooney pounced to score a 78th-minute winner as his side stunned eternal rivals Liverpool with a smash-and-grab 1-0 victory at a freezing Anfield on Sunday.
Presiding over his first game against United, Liverpool manager Jurgen Klopp watched his team dominate, but Rooney punished their profligacy with his fifth goal in four games, a close range snapshot after Marouane Fellaini had hit the bar.
It was United's first shot on target, but it was enough to give visiting manager Louis van Gaal his fourth win over Liverpool in four games and a first away victory since the 2-1 success at Watford on November 21.
Victory took United to within two points of the Champions League places and allowed them to reclaim fifth place from West Ham United, leaving Liverpool six points back in ninth place, their top-four hopes fading.
They may be England's two most decorated clubs, but Liverpool and United are not this season's leading contenders and a scrappy, shapeless first half reflected both clubs' recent difficulties.
Both teams had drawn 3-3 on their previous outings -- Liverpool at home to Arsenal, United at Newcastle United -- but there was to be no frenzied attacking to warm the 43,865 shivering souls at Anfield.
What quality football there was came chiefly from Liverpool and, in particular, Roberto Firmino, preferred once again to Christian Benteke as the nominal frontman.
He was involved in two early chances, first drilling narrowly wide after Jordan Henderson, freed by Lucas Leiva, had seen a header palmed away by the outrushing David de Gea and then releasing James Milner to slice wide with a fine, half-volleyed pass.
It was from a Firmino flick, meanwhile, that Henderson flashed a shot across goal and wide after a neat move also involving Adam Lallana.
The Brazilian looked poised to put Liverpool ahead six minutes before half-time, but as he cocked his right foot to shoot, Anthony Martial nipped in to intervene.
A ragged half for the visitors ended with Ashley Young hobbling off after appearing to injure his groin, with youngster Cameron Borthwick-Jackson coming on.
Stationed out on the left, Martial had to wait until first-half stoppage time for a sight of goal, but after driving into the box, his shot was blocked by Mamadou Sakho.
Injured United trio Michael Carrick, Phil Jones and Marcos Rojo were among the fans in the away end and they could only look on with concern as Liverpool's dominance continued in the second half, De Gea saving with his feet after Emre Can had flummoxed Chris Smalling with a step-over.
Martial threatened in the 56th minute, fizzing a shot wide after Borthwick-Jackson's cross was deflected into his path, but Liverpool were soon back on top.
De Gea fielded a side-foot effort from Henderson and then plunged to his right to parry an effort from Can before springing up to claw away Firmino's cross from the rebound.
Van Gaal sent on Juan Mata, match-winner in United's 2-1 victory at Anfield last March, and Memphis Depay, but still Liverpool came, Mamadou Sakho heading Milner's cross over.
They could not make their pressure count, however, and with 12 minutes remaining Rooney made them pay by slamming the ball past Simon Mignolet after Fellaini's header came back off the bar.
Liverpool's best chance of an equaliser fell to Firmino, but he could not control Milner's mishit shot right in front of goal and as his disbelieving glance at the linesman testified, there was no offside flag to spare his blushes.