Roberto Firmino and Mohamed Salah combined for both goals at the beginning and end of the first half as Liverpool returned to winning ways in the top flight, handing Jurgen Klopp his 50th Premier League victory as manager.
Perhaps Southampton's defence were guilty of giving their opponents too much time and space, but it is impossible to account for an assist of that nature from Firmino, and Salah is ruthless in front of goal when given a chance.
In the 18th minute, Southampton went close through Pierre-Emile Hojbjerg who failed to beat Loris Karius one on one.
Salah missed a huge chance to move level with the Englishman when he side-footed into the side-netting with the goal at his mercy after Alex McCarthy had saved Firmino's initial effort 20 minutes from time.
Van Dijk has not had the start he would not wanted to his Liverpool career after being dropped for their game against Huddersfield following a string of underwhelming performances.
It was satisfying to see attacking intent at the Hawthorns as we managed to score three goals away from home and should've scored more!
Firmino struck early after Southampton centre-back Wesley Hoedt's mistake, as the Dutchman horribly misjudged a Liverpool ball forward and gifted possession to the last player on the pitch that the Saints should allow to have the ball, Salah.
"Unfortunately they're not in a good position right now, but as a Liverpool player I am happy with the win". The Tottenham striker has recorded 23 goals this term. When you play against this side, I said before, you have to do everything nearly perfectly.