Chelsea's poor form continued as they went down to a 1-0 defeat to Southampton at Stamford Bridge, while they also lost captain Cesar Azpilicueta to what appeared to be a serious injury.

The Spaniard received an accidental boot to the head from Sekou Mara while defending a corner in the 74th minute, leading to 10 minutes of treatment on the field before he was taken off.

James Ward-Prowse's first-half free-kick had given the visitors the lead against Graham Potter's side, extending Chelsea's winless league run to four games.

Southampton caretaker manager Ruben Selles will be happy with the three points his side earned as they picked up a big result in their first game since the sacking of Nathan Jones.

It was Saints who made the brighter start, with Paul Onuachu forcing a save from Kepa Arrizabalaga inside five minutes.

Chelsea gradually found a foothold in the game, with Azpilicueta trying his best to get his team on top in a low-quality encounter.

It was his foul on Stuart Armstrong outside his own box in the 45th minute that allowed Ward-Prowse to dip a trademark free-kick over the wall and into the bottom-left corner of the goal just before half-time.

With a deficit to overturn, the hosts went close several times after the interval, with Romain Perraud making a dramatic clearance to deny substitute Raheem Sterling off the goal-line.

After such a lengthy pause for Azpilicueta's treatment, both teams struggled for cohesion following the restart, but Saints clung on for a crucial victory.

What does it mean? Chelsea chill continues

Since teams returned from the World Cup in December, the Blues have mustered just two wins in nine league games.

They have not had a Premier League victory since they edged Crystal Palace almost five weeks ago. For Potter, the writing may be on the wall.

Not silver for Sterling

Having arrived from Manchester City last year determined to reassert his place in the England set-up, it is fair to say the winger has struggled at Stamford Bridge.

He was still the biggest offensive performer for his side today, despite only playing the second half, with four shots. But just one on-target highlights the flaws in the Blues' attack.

Ward-Prowse closes in on Beckham record

The Southampton skipper has built a reputation as a set-piece specialist, with a prolific line in direct goals courtesy of free-kicks.

He now has 17 to his name in the Premier League, just one behind the record of 18 held by David Beckham.

Key Opta facts

- Southampton have completed the league double against Chelsea for the first time since the 1987-88 season.
- Chelsea lost at home to the team starting the day bottom of the Premier League table for the first time since April 2014 vs Sunderland (2-1).
- The Blues have lost three of their last six Premier League home games (W2 D1), as many defeats as in their previous 25 league games at Stamford Bridge combined (W13 D9).
- Their profligacy remained as they had 17 attempts at goal (five on target), their highest number of shots without scoring at home in the Premier League since May 2021 against Arsenal (19).
- Southampton committed 24 fouls, the most in a Premier League game so far this season.

What's next?

Southampton travel to fellow bottom-three side Leeds United next Saturday while Chelsea head to north London for a derby with Tottenham a week on Sunday.