Southampton striker Danny Ings put a dent in his former club's title aspirations with his early strike sealing a 1-0 win over Liverpool.
There were less than two minutes on the clock when Ings lobbed goalkeeper Alisson to give Saints the lead, their first goal since December 16.
The Reds have struggled for form since their 7-0 thrashing of Crystal Palace on December 19, with draws at home to West Brom and at Newcastle falling before this defeat in Hampshire.
Although the champions hold on to the Premier League top spot on goal difference, Jurgen Klopp's men failed to take the opportunity to go three points clear of rivals Manchester United, who now have a game in hand over the champions.
For Saints it was their first win since a 3-0 victory over struggling Sheffield United on December 13, and the first time under Ralph Hasenhuttl they had taken points off Liverpool.
His side had been given the perfect start after Thiago Alcantara gave away an early free-kick on his return to the starting line-up. James Ward-Prowse found Ings with a clever set-piece and the 28-year-old took a touch before expertly lobbing into the far corner.
The striker benefited after a lapse in concentration from the usually reliable Trent Alexander-Arnold in a makeshift Liverpool defence, with Klopp naming his 10th centre-back pairing in 17 top-flight matches this season.
It took until the 33rd minute for Liverpool to create their first significant chance of the game, when Sadio Mane cut in and curled the ball towards goal, but his effort was over the bar.
Liverpool had a penalty shout in the second-half when Georginio Wijnaldum's shot hit Jack Stephens' arm. VAR took a look but did not overrule the referee's onfield decision.
Despite their pressure, the visitors' first shot on target came in the 75th minute when Mane found himself in space inside the area, but his shot lacked power.
Alisson was given a late reprieve when Southampton almost doubled their lead after coming 30 yards to clear the ball, only for substitute Yan Valery to get there first - but Jordan Henderson was able to get back and clear the ball.
SOUTHAMPTON: Forster, Walker-Peters, Bednarek, Stephens, Bertrand, Djenepo (Tella, 32 mins), Ward-Prowse, Diallo, Armstrong, Ings (N'Lundulu, 77 mins), Walcott (Valery, 82 mins). Unused subs: Long, Smallbone, Vokins, Ramsay, Lewis, Chauke.
LIVERPOOL: Alisson, Alexander-Arnold (Milner, 77 mins), Henderson, Fabinho, Robertson, Wijnaldum, Oxlade-Chamberlain (Shaqiri, 57 mins), Thiago, Salah, Firmino, Mane.Unused subs: Jones, Minamino, Origi, R Williams, Phillips, Kelleher, N Williams.
Referee: Andre Marriner (West Midlands)
Man of the match: Ibrahima Diallo
Match rating: 7/10