Sadio Mane scored either side of half time while Philippe Coutinho, Emre Can, Roberto Firmino and Georginio Wijnaldum all got on the scoresheet as Liverpool delivered another five-star performance in front of their own supporters.

It took Liverpool just seven minutes to create their first clear-cut chance of the match, but Firmino was unable to make a good connection from eight yards out after being found by Coutinho.

Lucas Leiva should have gotten on the scoresheet when the ball fell invitingly for him at the back post, but he sent his close-range effort straight at Heurelho Gomes.

The opportunities continued to come for Liverpool, and after Coutinho had fired wide from 10 yards out and Firmino poked wide from a similar distance, the Merseyside team finally went in front after Mane glanced a header into the far corner after meeting Coutinho's cross.

Three minutes later, Coutinho capped a mesmeric opening 30 minutes with a low drive into the net from 20 yards, with the goal also seeing Gomes replaced by Costel Pantilimon after he suffered a knee injury when diving for the ball.

There was no let up from Liverpool, and two minutes before the break, Can made it three when he headed into the bottom corner after being found at the back post by Adam Lallana.

Coutinho and Jordan Henderson had both gone close after the restart before Liverpool added another to their tally as Firmino tapped home from close range and Lallana contributed his second assist.

The scoring was not over for Jurgen Klopp's men as Mane made it five before the hour mark after converting from six yards out after meeting Firmino's delivery.

A clean sheet became Liverpool's priority as the game entered the final 30 minutes but Watford started to look the more likely to score a sixth goal of the match as Etienne Capoue and Miguel Britos both forced solid saves out of Loris Karius.

However, the goalkeeper was powerless to prevent Daryl Janmaat grabbing a consolation goal for the Hornets as the right-back calmly slotted the ball into the bottom corner with his left foot.

Klopp introduced Daniel Sturridge and the striker struck the crossbar with two efforts in the space of 10 minutes, the second of which forced an outstanding save from Pantilimon who managed to get fingertips to his 25-yard effort.

However, the goalkeeper contributed to Liverpool bagging a sixth in added-on time after he parried Sturridge's shot into the path of Wijnaldum, who took his time before converting the rebound to cap a memorable afternoon for his side.