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.