Mane and slick Southampton deepen Chelsea gloom

Having taken an early lead through Willian, Mourinho's side collapsed alarmingly, with Steven Davis levelling for Ronald Koeman's team before second-half goals from Sadio Mane and Graziano Pelle wrapped up the win.

Mourinho had suffered just one home league defeat in over four seasons at Chelsea coming into the season, but has now already seen his side beaten twice at Stamford Bridge during the current campaign, following an earlier defeat by Crystal Palace in August.

There were few signs Chelsea are ready to return to the form that saw them cruise to last season's title and the growing discontent around the club was apparent when home supporters greeted the final whistle with a chorus of boos.

By his own admission, this is the worst spell of Mourinho's career and the manager this week found himself in the unfamiliar position of being forced to defend his methods following reports of discontent within his squad.

The failure to beat struggling Newcastle United seven days previously had summed up Chelsea's problems, with Mourinho describing the first-half display at St James' Park as being "on a scale of one to 10, minus one".

That was followed by defeat at Porto in the Champions League and the Portuguese reacted by making four changes.

Skipper John Terry returned to make only his second start in six games, while Radamel Falcao was handed his first league start of the season in place of the suspended Diego Costa.

After the recent turmoil, Chelsea needed an early break to settle any nerves and it came after just 10 minutes when Willian punished the visitors after Oriol Romeu had fouled Eden Hazard.

- Cahill, Terry at fault -

Curling the free-kick in from the left-hand side of the box, the Brazilian directed the set-piece beyond goalkeeper Maarten Stekelenburg and into the top-right corner.

Had Oscar managed to beat Stekelenburg with a curling shot midway through the half, the home side might have gone on to dominate.

Instead, though, they allowed Southampton to come back into the game with Koeman's side growing in confidence and fuelled by a sense of injustice when a strong appeal for a penalty was turned down after Mane appeared to have been tripped by Ramires.

Mane was becoming increasingly influential and his threaded pass presented Ryan Bertrand with the chance to mark his return to Stamford Bridge with a goal, only for the left-back to be denied by Asmir Begovic.

The equaliser came two minutes before the interval when Pelle held off Gary Cahill and chested Jose Fonte's long ball into the path of Davis, who struck the ball on the full past Begovic from 20 yards.

Chelsea's belief appeared to have disappeared when the game resumed after the break and it took another excellent Begovic save and a block by Gary Cahill to repel efforts from Mane.

Both Cahill and Terry appeared vulnerable to the pace of Mane and both defenders were at fault when the Senegal forward put the visitors ahead in the 60th minute.

First, Cahill lost possession deep inside his own half, then Terry was easily turned by Mane as the forward collected Pelle's pass and shot beneath Begovic.

Worse was to come for Chelsea when Hazard's misplaced pass was intercepted near halfway by Pelle, allowing Mane to break towards the home penalty area before returning the ball to Pelle, who shot inside the far post.