James Ward-Prowse stunner sees Southampton beat Chelsea at Stamford Bridge

Graham Potter's side have now only won once in all competitions since the end of December, while it is a second straight defeat for the capital giants following their 1-0 reverse to Borussia Dortmund in the Champions League last week.

The result has left Chelsea in 10th position in the table, 10 points behind fourth-placed Newcastle United, who now have a game in hand.

Southampton remain bottom of the division, but the Saints would have gained huge confidence from the result and performance, with James Ward-Prowse's stunning free kick proving to be the difference in the team's first match since the departure of Nathan Jones as head coach.

The Saints had a golden chance to take the lead in the third minute when a mistake from Benoit Badiashile led to Kamaldeen Sulemana breaking into a dangerous position, but the attacker saw his effort saved by Kepa Arrizabalaga, before Start Armstrong saw a strike cleared away by Kalidou Koulibaly.

The visitors again came close in the 16th minute, with Paul Onuachu heading a Ward-Prowse cross wide of the post before Noni Madueke saw a left-footed strike kept out by Southampton goalkeeper Gavin Bazunu.

Cesar Azpilicueta struck one into the side-netting for Chelsea in the 28th minute, before Bazunu made a smart save to keep out a low strike from Datro Fofana in the 41st minute, but Southampton were restricting Chelsea to half-chances rather than clear openings at Stamford Bridge.

The visitors then managed to take the lead in the closing stages of the first half, with set-piece specialist Ward-Prowse brilliantly firing a free kick into the back of the Chelsea net.

Raheem Sterling and Wesley Fofana both came off the home side's bench at the interval, and the former set up Mason Mount with a clever cross in the 50th minute, but the attacker got his header all wrong.

Sterling was involved again in the 52nd minute, striking towards goal after smart work from Badiashile, but Jan Bednarek was on hand to make an important block.

The pressure from Chelsea was increasing, though, and Azpilicueta just missed the target with a low strike in the 56th minute after the defender was found by Mateo Kovacic.

Sterling then saw a goal-bound effort blocked by Ainsley Maitland-Niles before the England international had a header cleared off the line by Romain Perraud, with Romeo Lavia clearing the follow up over the crossbar.

Adam Armstrong actually came close to a second for Southampton in the 73rd minute, but the forward's close-range effort was saved by Kepa, with Chelsea living dangerously at Stamford Bridge.

There were 12 minutes of added time in London, and Joao Felix and Mykhaylo Mudryk both came close late on, but Southampton held on, with Ruben Selles securing a win in his first game in caretaker charge.

Next up for Chelsea is a trip to Tottenham Hotspur in the Premier League on February 26, while Southampton will be in action one day before away to fellow strugglers Leeds United.