Watford player, Miguel Britos gave his side a point in a thrilling encounter after heading in from close range to deny Salah a win in his Liverpool debut.
The Egyptian had a good game on his debut for Liverpool after scoring a goal to ensure his team gets the Victory but Watford had other options.
Stefano Okaka gave Watford the lead as the hosts were on course for Victory but Mane scored after a sweet team work to revive the hopes of the reds before Abdoulaye Doucoure pulled the cheese nut out of the fire to mount pressure on Liverpool.
Roberto Firmino equalised from the penalty spot to bring the reds level but Salah turned the ball home from close range two minutes later to put the visitors in front for the first time.
Liverpool would hope to have Barcelona target, Coutinho for the next game as he missed the game against Watford due to injury.