With both teams out of form, Gary Neville had predicted this match would resemble the "Dog & Duck versus the Red Lion", but only one team defended like a Sunday league team in this grudge match.
Liverpool's marking and composure at the back was all over the place and United took full advantage romping to a 3-0 victory over their biggest rivals.
Wayne Rooney was given more than enough space to sweep home Antonio Valencia's cross and put the hosts ahead.
Juan Mata then nodded in at the far post to double United's lead - although replays showed he was offside when he touched Robin van Persie's flick on it.
And the most embarrassing goal from Liverpool manager Brendan Rodgers' perspective came when Dejan Lovren fluffed his clearance and Van Persie was given ample time to beat Brad Jones.
Rodgers took a big gamble by dropping Simon Mignolet for Jones and starting Raheem Sterling as a lone striker.
And the move backfired quite spectacularly
Sterling wasted three good chances to score while Jordan Henderson also missed a sitter.
Rodgers turned to Mario Balotelli to inspiration at half-time, but the Italian also spurned opportunities, although that was partly down to David de Gea, who once again put in an outstanding display.
United's sixth consecutive win moves them to within eight points of Premier League leaders Chelsea.
The repercussions for Liverpool are more serious
Rodgers insisted he was the right man to lead the Reds out of the mire before kick-off, but he walked down the tunnel to taunts of "you're getting sacked in the morning" from the home fans.
Rodgers' team routed United 3-0 here in March
Now they are ninth in the table, some 18 points off the summit.
It will not take long for Liverpool supporters' patience in their manager to run out if they keep performing like this.
There was no sign of the impending Liverpool meltdown early on.
Rodgers' team pressed high up the pitch and they could not get out of their own half in the opening five minutes.
United lacked composure and Marouane Fellaini was the worst offender
The big Belgian could not complete the simplest of passes and he hacked down Adam Lallana to receive a booking.
The home crowd groaned as United passed the ball backwards or sideways.
Rodgers' tactical gamble looked to be working at the start
Sterling - playing as a lone striker - caused Phil Jones, Jonny Evans and Michael Carrick no end of problems with his pace.
His finishing let him down in the 12th minute when he stole in behind the defence and shot straight at De Gea.
Just 25 seconds later Rooney showed his England team-mate how it should be done.
Rooney made a late run from deep and he was picked out by Valencia, who nutmegged Joe Allen to give himself time to deliver the precise pass
Jones dived the wrong way and Rooney swept home from 15 yards before he was mobbed by his jubilant team-mates.
Liverpool's finishing let them down three more times before half-time.
Steven Gerrard tried - and failed - to beat De Gea from long range and the Spaniard thwarted Sterling again after he turned Jones with ease
Alberto Moreno also broke into the box but his touch was shoddy and Valencia rescued United.
Neville must have enjoyed the first half
Some of Liverpool's passing did resemble that of a pub team.
United were putting their lead in danger though with some rash challenges
Jones, Evans and Rooney all went into the book for fouls on Phillippe Coutinho.
Rodgers had to replace Glen Johnson with Kolo Toure after the right-back pulled up with an injury.
United did not look entirely convincing on the attack, but they still doubled their lead in controversial circumstances.
Van Persie flicked Ashley Young's cross into the path of Mata, who nodded in his fifth of the season
The Spaniard was at least a yard offside but linesman Michael Mullarkey did not flag and the goal stood.
Balotelli was booed when he came on at half-time, while Liverpool's b est chances continued to fall to Sterling
The England winger picked up a short back pass from Evans, but could not finish thanks to the calm brilliance of De Gea
De Gea was United's saviour again when he tipped Balotelli's shot on to the bar
Henderson spurned another good opportunity when he headed over from 10 yards.
United were far more clinical in front of goal
Van Persie delivered the fatal blow with 19 minutes to go
He will struggle to score an easier goal all season.
Lovren had all the time in the world to hook Rooney's square pass clear, but instead he fluffed it to Mata and he picked out the unmarked Van Persie, who slotted the ball home
Game over.
Source : PA
Source: PA