Magic Salah does the trick as Liverpool crush United
Mohamed Salah scored a hattrick as Manchester United were ripped apart by relentless rivals Liverpool to leave Ole Gunnar Solskjaer under the most intense scrutiny of his near three years in charge.
The 202nd meeting of two of English football's biggest rivals will live long in the memory after Jurgen Klopp's men ran amok and recorded the club's biggest ever win at Old Trafford.
Liverpool were as impressive as United were poor, with scintillating Salah's treble complementing early goals from Naby Keita and Diogo Jota in a 5-0 rout in which substitute Paul Pogba was sent off.
Sir Alex Ferguson was seen shaking his head in disbelief after the fifth goal, with the visiting fans chanting Solskjaer's name during an embarrassing display that will test the Old Trafford hierarchy's support of their manager.
United’s unsteady defence was exposed by Liverpool within five minutes.
Hapless Harry Maguire and Victor Lindelof were caught out of position, with Luke Shaw too late to step up in an attempt to play Salah offside. The Egyptian played through Keita to fire home in front of a stunned Stretford End, whose nightmare had just begun.
Roberto Firmino was denied by David De Gea and Salah struck wide as United wobbled, with Liverpool grabbing a second in the 13th minute after Marcus Rashford had fired narrowly wide at the other end.
A mix-up between Maguire and Shaw allowed Keita to play wide for Trent Alexander-arnold to fizz in a low cross for Jota to turn home at the far post as United paid for more terrible defending.
The open pattern of play continued as Salah and Rashford traded efforts, before Klopp's side put their foot on the hosts' throat.
Liverpool built up smartly and reacted quickest when Salah's shot was blocked, with the forward bursting towards goal as United's cumbersome defence watched Keita cross for him to fire home.
Frustrated Cristiano Ronaldo was perhaps fortunate to avoid a red card for swinging wildly at the ball as Curtis Jones lay on the deck, but there was still time for United to unravel further.
Maguire was pulled out of position and the defence panicked, allowing Salah to strike at the far post in the fifth minute of first-half stoppage time.
Half-time introduction Pogba was dispossessed five minutes after the restart and Jordan Henderson played a fine ball with the outside of his foot through for Salah to direct past De Gea and complete his hat-trick.
The hosts thought they had clawed one back when Ronaldo beat Alisson, only for the goal to be ruled out for offside after a VAR review.
Stuart Attwell was the man at Stockley Park and soon advised referee Anthony Taylor to check the monitor having booked Pogba for a late challenge on Keita. Upon review, the card was upgraded to red.
Man Utd: De Gea, Wan Bissaka, Lindelof, Maguire, Shaw, Mctominay, Fred, Greenwood (Pogba 46), Bruno Fernandes (Cavani 62), Rashford (Dalot 62), Ronaldo.
Subs not used: Bailly, Lingard, Sancho, Henderson, Matic, van de Beek.
Liverpool: Alisson, Alexander-arnold, Konate, van Dijk, Robertson, Keita (Oxlade-chamberlain 64), Henderson, Milner (Jones 27), Salah, Firmino (Mane 77), Jota. Subs not used: Gomez, Adrian, Minamino, Tsimikas, Origi, Matip.