Mane took just nine minutes to put Liverpool ahead at Vicarage Road and reach his milestone, converting Salah's brilliant outside-of-the-boot pass with a first-time finish.
The Senegalese becomes the 31st player to join the century club just a few weeks after teammate Salah added his name to the list.
Mane, 29, scored his first Premier League goal for Southampton in a win against Stoke City in October 2014. He finished that season with 10 league goals, including the fastest hat-trick in Premier League history (2 minutes, 56 seconds) in a 6-1 win against Aston Villa in the final game of the 2014/15 season.
He scored 21 league goals in two seasons for the Saints before earning a £34 million move to Liverpool at the start of the 2016/17 campaign.
Since then Mane has gone on to form a prolific triumvirate alongside Salah and Roberto Firmino, scooping the joint-Golden Boot award with career-high 22 goals in 2018/19.
The following season, Mane's 18 league goals helped Jurgen Klopp's side clinch the Premier League title.
The gallery above features every player to score 100 Premier League goals. To move on to the next photo, click on the arrows or if using a mobile device, simply swipe.