With Tottenham Hotspur and Manchester United not in league action due to their involvement in the FA Cup, it was the ideal opportunity for Jurgen Klopp's men to apply pressure on their rivals and the Reds responded with a dominating performance to prove that they weren't dwelling on last week's loss to the Red Devils.
The Reds will face Manchester City in the quarter-finals of the Champions League and he is looking forward to the fixtures.
"His goals are so important for us".
Salah turned provider for Roberto Firmino's goal in the 49th minute with a pinpoint cross that the Brazilian guided into the net with an audacious mid-air back-flick.More news: Top Pakistan Security Official to Visit Afghanistan for Crucial Talks
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There was still time for the Egyptian super star to grab his fourth of the game as Salah was on hand to slam home the rebound after Danny Ings saw his effort saved by Karnezis.
Watford arrived at Anfield having lost seven of their past eight away games in the Premier League, and never looked likely to avoid another defeat after conceding just four minutes in.
The only negative of a comfortable afternoon for Liverpool was the sight of Emre Can hobbling off with a hip injury before half-time, but the German's absence didn't disrupt their attacking rhythm.
Liverpool's Mohamed Salah celebrates with manager Juergen Klopp and the match ball after the match.
Reflecting on Salah's performance against Watford, Liverpool boss Jurgen Klopp said: "I think it's quite exceptional". His consistency is very good for us. I feel it has my style of football.