'Darkest day': Man United 'rock bottom' after unprecedented mauling

Pictured left, Manchester United manager Ole Gunnar Solskjaer and Liverpool's Mo Salah on the right.
Manchester United manager Ole Gunnar Solskjaer (left) described Liverpool's 5-0 win as his 'darkest day' at the helm of the club. Pic: AAP

Manchester United have made unwanted history after crashing to the club's worst ever defeat to fierce rivals Liverpool at Old Trafford

Mohamed Salah scored a hat-trick as Liverpool humiliated United, romping to a stunning 5-0 Premier League victory to heap even more pressure on under-fire manager, Ole Gunnar Solskjaer.

'FELT IN DANGER': Explosive details heard in football sex tape trial

'UNBELIEVABLE': Cristiano Ronaldo's act of 'perfection' stuns world

'INAPPROPRIATE': Fans clipped over response to Saudi takeover of club

United were 4-0 down at halftime after 45 minutes of shambolic defending that saw large sections of the home crowd exiting for the turnstiles.

The sense of chaos and calamity was amplified for United when substitute Paul Pogba was sent off on the hour mark just 15 minutes after coming on at halftime.

The United hierarchy have shown faith in Solskjaer throughout difficult periods in his nearly three years in charge but will come under pressure to rethink their loyalty to their former player after such an embarrassing performance and result.

Solskjaer admitted after the game that it was his "darkest day" as United manager and while insisting the side is "close" to where he wants it to be, evidence points to the contrary.

"We know we are rock bottom, we can't feel any worse than this," said Solskjaer, who said though that he had no intention of falling on his sword.

"I have come too far, we have come too far as a group. We are too close to give up now."

As well as being United's worse loss against Liverpool at Old Trafford, it was the club's biggest defeat in the fixture since the 7-1 thrashing at Anfield in 1895.

The chastening defeat was also the first time since 1955 that United have lost by a margin of five or more goals at home without scoring a goal.

The football world was understandably scathing of Manchester United's performance on social media.

Jurgen Klopp's Liverpool, who are in second place, a point behind leaders Chelsea, looked every bit the title contenders they are with Salah continuing his remarkable run of scoring form - finding the target for the 10th game in all competitions.

"What we did in the last third was insane. Pressing high, winning balls, scored wonderful goals," said Klopp.

"5-0, I couldn't be happier, it is exceptional. Absolutely outstanding," added the German.

Liverpool took the lead when Luke Shaw sloppily played Salah onside and the Egyptian's pin-point cross was turned in by Naby Keita.

Shaw was at fault again, eight minutes later, when he and Harry Maguire got in each other's way and Keita took advantage moving the ball outside to Trent Alexander-Arnold whose low ball across the face of the goal was slid in by Diogo Jota.

Salah then increased the lead, when he and Keita combined.

Liverpool's Mohamed Salah is seen here celebrating a goal after scoring against Manchester United.
Liverpool forward Mohamed Salah was Manchester Uinted's chief tormentor at Old Trafford. Pic: Getty

There was simply no authority or sense of discipline in the United defence and Salah made it four with a near post conversion of a low ball in from Jota.

It was the first time United had been 4-0 behind at the interval in the Premier League era and they were loudly booed off the field.

It took just five minutes after the break for Salah to complete his hat-trick with a trademark clinical finish after Jordan Henderson won the ball from Pogba in midfield and curled a pass into the path of the forward.

United's day got worse as they had a Ronaldo goal over-ruled for offside by VAR and then Pogba was red carded for a two-footed tackle on Keita, 15 minutes after coming on.

It was a ruthless display from Liverpool and a calamitous one from their rivals and it remains to be seen just what the fallout from this humiliation will be.

with AAP

Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.