Villa's record signing Watkins had never scored a Premier League goal before kick-off and 45 minutes later he had the match ball, as the home side took advantage of Liverpool's high line and individual mistakes.

Captain Grealish scored their final two goals after assisting three.

It is the first time Liverpool have conceded seven goals since 1963 and only their fourth Premier League defeat since 3 January 2019. Villa, who escaped relegation on the final day of last season, overtake them in the table with their best start since 1962.

Villa's first was the result of a huge error by Adrian. The Reds stand-in keeper passed the ball straight to Grealish, who cut it back for Watkins to side-foot in from eight yards.

Watkins' second was excellent as he cut in from the left and smashed into the top corner.

Mohamed Salah looked to have restored order when he scored for the Reds, but John McGinn's deflected volley two minutes later put Villa's lead back to two.

It got even better when Watkins headed in from Trezeguet's cross to become the first player to score a Premier League hat-trick against Liverpool since Dimitar Berbatov for Manchester United 10 years ago.

Villa debutant Ross Barkley, a boyhood Evertonian, was excellent and added a fifth after the break from just outside the box - from Grealish's third assist.

Salah made it 5-2 from Roberto Firmino's pass on the hour-mark but then Grealish smashed in Villa's sixth before latching onto McGinn's raking pass to add another.

This is the first time in 18 attempts that Villa have beaten the reigning champions at home - the last was a 3-2 win over Arsenal in December 1998.

There have been many surprising results this season - including Tottenham's 6-1 win at Manchester United earlier on Sunday - but none can beat this for sheer shock value.

The game that defies all logic

This is a result which makes no sense - apart from the fact Aston Villa were remarkable and clinical and Liverpool were unbelievably bad.

A team who almost got relegated last season beat the defending champions - who barely ever lose - 7-2.

It is one thing to identify Liverpool's weaknesses but quite another to take advantage of them in such a sensational way.

Villa are now unbeaten in seven league games, including the run that saw them stay up at the end of last season, and have won all three league matches this season.

Dean Smith's side managed to get in behind Liverpool's high defensive line with ease in the first half and Watkins, who was the Championship's top scorer last season and cost Villa a club record £28m, was the chief beneficiary.

He took advantage of Adrian's error for the first with his left foot and chased onto Grealish's pass before cutting inside Joe Gomez and firing home with his right.

Watkins got his perfect hat-trick - in more ways than one - before the break, nodding into an empty net after Barkley's deep free-kick was collected by Trezeguet who clipped the ball into the six-yard box. He also crashed an effort onto the crossbar as Villa chased an eighth goal late on.

Three more goals followed in an equally frenetic second half. Grealish picked out Barkley, whose 20-yard strike was helped into the top right-hand corner by a flick off the leg of Trent Alexander-Arnold. Grealish then scored via a Fabinho deflection before running onto a McGinn pass to add a famous seventh.

What now for Villa? With a performance like this and three wins from three their thoughts will be a lot, lot higher than a relegation battle.

What on earth was that from Liverpool?

Liverpool were missing first-choice goalkeeper Alisson through injury and Sadio Mane and Thiago, who have both tested positive for coronavirus. But nothing could excuse this performance, surely the worst of manager Jurgen Klopp's illustrious era.

Even last year when they put out their under-23 team to face Villa in the Carabao Cup, as the first team contested the Club World Cup, that only ended in a 5-0 defeat.

Liverpool were completed wretched. The tone was set from the moment Adrian overhit a simple pass to Joe Gomez, which went straight to Grealish to set up the opener.

Several of Villa's goals took advantage of Liverpool's high defensive line. They just could not deal with the guile of Grealish and Barkley and the finishing of Watkins.

Salah's double will count for nothing.

Will Klopp treat this game as a one-off anomaly, or will the the manner of the defeat be more of a concern for the German? 

The Uruguayan was one of four arrivals on deadline day, as United’s transfer window finally kicked up a gear.

Cavani represents the attacking addition that Solskjaer had been searching for throughout the window, as he looked to add additional firepower to his squad.

Much of the summer was spent chasing Jadon Sancho, while Ousmane Dembele and Ismaila Sarr were both linked with Old Trafford switches. 

However, Cavani did finalise a move before the window closed, signing a one-year deal, with the option to extend that for a further 12 months next summer.

The 33-year-old joins United after a prolific spell in the French capital. During his seven seasons with PSG, he won six Ligue 1 titles, scoring more than 200 goals in the process.

He will hope to hit the ground running in the Premier League and revealed it was a chat with United’s boss that strengthened his desire to make the move. 

“I have had a conversation with the manager and this has increased my desire to wear this beautiful shirt,” he told the club’s official site.

“ Manchester United is one of the greatest clubs in the world, so it is a real honour to be here. I’ve worked really hard during the time off and I feel eager to compete and represent this incredible club.

"I have played in front of some of the most passionate supporters in football during my career and I know that it will be the same in Manchester. I cannot wait to experience the Old Trafford atmosphere when it is safe for the fans to return.” 

Along with Cavani, Brazilian full-back Alex Telles and young wingers Facundo Pellistri and Amad Traore signed for United as they look to put Sunday’s thrashing by Tottenham behind them.

And Solskjaer believes Cavani’s arrival will provide a huge spark to his young squad, when they return to Carrington after the international break.

"The opportunity for our young players to learn from one of Europe’s top goalscorers over the last 10 years is fantastic and it will really benefit them going forward," he said. "Edinson knows exactly what it takes to succeed and we are all looking forward to seeing him make an impact at Manchester United.”