Liverpool's Premier League title defence suffered a setback as they fell to their second loss of the season at Southampton.
Danny Ings' superb second-minute lob over Reds goalkeeper Alisson, from a James Ward-Prowse free-kick, settled the contest against his former club.
The goal marked the 50th Premier League goal of Ings' career between stints at Southampton (36), Burnley (11), and Liverpool (3).
Jurgen Klopp's Liverpool side remain top of the table on goal difference but have taken only two points from the past nine available.
Both Manchester United and Manchester City will leapfrog the reigning champions if they win their games in hand.
Southampton's first win in five Premier League games sees them rise to sixth.
Liverpool's next match in the Premier League will be at home against Man United on Jan. 17. Southampton will visit Leicester on Jan. 16 after hosting Shrewsbury in the FA Cup seven days before.
Meanwhile Arsenal defender William Saliba is set to complete a loan move to Nice for the rest of the season.
He has played for Arsenal under-21s but has yet to play for the senior team and there is a desire for the teenager to get more game time.
The French youth international signed a five-year deal with Arsenal and his long-term future remains at the club.
Nice, who are 12th in France's Ligue 1, will pay all of Saliba's wages while he is on loan, which does not include a fee.