"In the end it is a good game for us. We adapted well to their three at the back. They changed again in the second half. We took advantage. There were spaces in the first half. A clean sheet too so a good performance," Jota said after the game.
"It is always easier when you start well with a goal at home. We knew in the past we have been 2-0 up and not won the game. But we did today and that is important. The most important is that we win.
"I take advantage of playing for a good team. Fortunately for me I can score goals and hopefully keep doing it."
Salah's assist means he has been directly involved in 25 goals this season across all competitions which is more than double that of any other Premier League player.
Thiago added Liverpool's third five minutes later. It looked like Southampton had headed the ball away from danger but Thiago hit it first time into the goal.
Van Dijk scored his first goal in 14 months on 52 minutes from near the penalty spot.