As reality checks go, the humiliation Liverpool handed out to Manchester United at a joyous and almost disbelieving Anfield was as brutal as it gets.

Liverpool's 7-0 win was a monument to the return of all the qualities that have driven success under manager Jurgen Klopp. Those same statistics piled up like rubble at the feet of a Manchester United side that simply crumbled.

The biggest beating in the history of this famous fixture; the 7-0 scoreline equalling the heaviest defeat inflicted on United; Liverpool scoring six goals in a truly remarkable 45 minutes in front of the Kop.

Joy for Liverpool. Pain for Manchester United.

United lost by the same margin to Blackburn Rovers in 1926, to Aston Villa in 1930 and to Wolverhampton Wanderers in 1931.

None of those will be mentioned in the same breath as this truly remarkable game because of who inflicted it and where.

This is why this win was celebrated so wildly by Liverpool's baying fans. This is why Manchester United will be so badly wounded.

This will be a day that will be remembered forever by everyone who witnessed it at Anfield - even those United supporters who will try to blank it from their memory but will find it impossible - and far beyond.

Liverpool have been scratching for the old certainties this season. The intensity. The passion. The ruthlessness. The controlled fury.

Unfortunately for United, it all came flooding back in a game that will go down in history. It certainly put the Red Devils' renaissance, shown by the EFL Cup win against Newcastle United at Wembley, on temporary hold.

Mohamed Salah's two goals made him Liverpool's record Premier League scorer with 129, overtaking Robbie Fowler despite playing 61 fewer games.

Salah's record shows the seismic impact he has had from pretty much the first day he arrived at Liverpool from Roma in June 2017 - and yet here he also took his place in what Klopp is building for the future.

The Egyptian netted two goals, almost expected given the fact he is also Liverpool's record scorer against Manchester United with 12.

But of great significance was the impact of two newcomers brought in as Klopp renews the attack that has served him so superbly - Darwin Nunez and Cody Gakpo.

This was the sight of an Anfield evolution as the pair gave a tantalising glimpse of the future.

Salah, Sadio Mane and Roberto Firmino formed one of the most potent tridents in world football in Klopp's first great team but the winds of change have been blowing.

Mane made his exit to Bayern Munich in the summer while Firmino announced on Friday that he would be leaving Liverpool at the end of the season.

Indeed, it was a sign of Liverpool's perfect scriptwriting on Sunday that the Brazilian emerged as a substitute to a rapturous reception and provided the perfect finale to this landmark game with the goal that made it 7-0 in front of the Kop in the closing moments.

Alongside those goals from Liverpool's old guard came two each from Gakpo and Nunez that hinted at the potency and promise within the next incarnation of Klopp's forward line.

Gakpo was a target for United manager Erik ten Hag before Liverpool stepped in to snatch him away from PSV Eindhoven in January - and here you could see what the attraction was.

He provided a smooth finish from Andrew Robertson's perfect pass to open up what had been, as remarkable as it sounds, a tight game for 43 minutes.

Gakpo scored Liverpool's third with a delicate flourish after brilliant work by Salah, before he was joined on the scoresheet by Nunez, who is now getting the goals his industry has deserved.

Nunez diverted Harvey Elliott's driven cross past United keeper David de Gea to put Liverpool 2-0 up then scored with another superb header from Jordan Henderson's ball in for the fifth.

Gakpo and Nunez are still early works in progress but they possess goals, variety and flexibility. Throw in the enduring, world-class Salah and this is another threatening Liverpool strike force in the making.

In the wider context, Klopp's side are now an ominous presence to Tottenham and Newcastle United in the fight for a top-four place.

Liverpool are only three points behind Spurs, who lost at Wolves on Saturday, while Newcastle look to be fading after a fine first few months of the season.

Klopp flagged up just how big this week was in shaping those ambitions and it has brought a deserved home win against Wolves before United were completely overwhelmed.

He said: "It was the push we wanted. It puts us in the right direction. Everyone has to know we are still around.

"It wasn't the case for a while but this was a proper show of what we can be and what we have to be from now on."

It was after a 4-0 loss at Liverpool in April that then Manchester United interim manager Ralf Rangnick announced: "They are six years ahead of us."

United's steps to recovery this season suggested the gap had been closed to an extent - but when Liverpool get it right, as they did here, it still resembles a chasm.