Liverpool scored three goals in a 16 minute first half spell to go top of the league for the first time in two and a half years.
Shortly before kick off the news filtered through that Arsenal and Spurs had played out a 1-1 draw in the North London derby. Following on from Man City's draw against Middlesbrough the door was ajar for Liverpool to end the weekend on top.
Liverpool met the challenge and had made it 5-0 with half an hour remaining.
The pre-match team-news highlighted two changes to the reds defence. Dejan Lovren was ruled out with illness, replaced by Lucas Leiva whilst James Milner returned to the starting line up - coming in for Alberto Moreno.
The reds started brightly and it was the unlikely figure of Lucas Leiva who should have put the reds in the lead. And not just on one occasion.
He had a header that went narrowly wide before moments later firing at Gomes from just 8 yards out following a Coutinho corner.
Firmino had an opportunity too in the early stages - he poked a shot wide under pressure. Coutinho fired one at the side netting and saw a shot rebound off the bar.
It was left to Sadio Mane to open the scoring. Coutinho and Milner exchanging passes at a corner before the little Brazilian crossed in for Mane to head in.
Just three minutes later it was 2-0. Firmino laying on the ball and Coutinho working himself some space before firing in a great shot from the edge of the area.
Watford were then forced into a goalkeeper change with Pantilimon coming on for Gomes. The Watford keeper had been unbeaten in his last 3 league games but had to depart with a knee injury.
With two minutes left of the half, Emre Can scored Liverpool's third - a well aimed header at the back post and nothing more than the reds deserved.
No player changes at half time and no change in Liverpool's intensity for the second half.
The reds were slicing through Watford at every opportunity.
Lallana sending the ball across the face of goal and Firmino on hand to make it 4-0.
Just minutes later it was five - Sadio Mane scoring his sixth goal of the Premier League season - he is LFC's top scorer in the competition.
The reds made some substitutions - Wijnaldum and Sturridge on for Mane and Lallana. The changes did unsettle Liverpool a bit - and they did concede a goal in the 75th minute.
Karius had already pulled off a fantastic save to try and protect the clean sheet but he couldn't deal with Janmaat's shot from inside the box. Milner lost the ball out wide and Henderson was guilty of giving the Watford man too much space to get his shot away, There was little Karius could do to stop it.
Still time for another Liverpool goal though - there always is these days.
Sturridge had been working hard for a goal - he had fired at the crossbar and at the side-netting. But the 90th minute goal was a debut one for Wijnaldum - Sturridge had taken the shot but the save rebounded to Gini who was in the perfect position for the tap in.
The Dutch international looked delighted - to him it seemed like the match-winner and Klopp smiled as another of one of his new signings is contributing with both assists and goals.
It would be hard to criticise Liverpool too much for conceding when they were leading 5-0 after 60 minutes. The most important thing is that LFC end the weekend top of the Premier League.
The international break is now upon us - and when it's over the reds face a trip to Southampton.
