Mohamed Salah adjusts his socks during a match at St. Mary's Stadium in Southampton. AP
Salah moved onto 19 goals and is three behind the league's top scorer, Leicester striker Jamie Vardy.
The Egypt international won the Golden Boot in his first year at Liverpool in 2017-18, and then shared the trophy with teammate Sadio Mane and Arsenal's Pierre-Emerick Aubameyang last season.
Salah wasted a couple of great chances late in the game to clinch his hat trick as Liverpool climbed to 92 points. The newly crowned champions need to win three of their final four matches to set a record for most points in a single top-flight season, which is currently held by Manchester City with its 100 from the 2017-18 campaign.
Jordan Henderson scored Liverpool's other goal, in the eighth minute, to build on the opener from Salah two minutes earlier.
Leandro Trossard replied for Brighton in the 45th minute, but Salah made the game safe with a near-post header from a corner by substitute Andrew Robertson in the 76th.
Liverpool extended their perfect start to the Premier League season as Mohamed Salah inspired an impressive 3-1 win over Arsenal,
The Egypt international, who signed a new five-year deal in 2018, was the top scorer at the club this season with 17 Premier League goals as they secured a 19th top-flight title with seven games to spare.
Liverpool, newly crowned Club World Cup winners, return to their main task — fighting for their first league title in 30 years — when they face their closest challengers Leicester City on Thursday.
The inaugural Gulf Youth Sport Expo, organised in partnership with Dubai Sports Council, will bring together all corners of the youth sports industry on September 17 for a day of presentations, panels, networking, and development.
The UAE’s Rashid Al Mulla says he is confident of extending one of the longest winning sequences in competitive international water sport in Italy at the weekend.
The Group 2 Dubai Duty Free Mill Reef Stakes, highlight of the Dubai Duty Free International Weekend at Newbury Racecourse on Friday and Saturday, has attracted 17 high-class two-year-olds at the five-day confirmation stage.