Southampton stunned Chelsea with a 3-1 win at Stamford Bridge to inflict further misery on Jose Mourinho and the Premier League champions tonight.

Willian fired the hosts into a 1-0 lead with an excellent free kick, but Steven Davis's fine volley just before half time ensured parity at the break.

Goals from Sadio Mane and Graziano Pelle then completed the scoring for the Saints in an error-laden second half from the Blues.

Here, Sports Mole analyses how the points were won on a dramatic night in West London.

Match statistics

CHELSEA
Shots: 10
On target: 3
Possession: 61%
Corners: 4
Fouls: 14

SOUTHAMPTON
Shots: 13
On target: 5
Possession: 39%
Corners: 6
Fouls: 14

Was the result fair?

One look at the statistics should prove that this was not a game that Chelsea dominated and could have won on another night, as is often the case when an elite team loses in their own backyard. It was a game that Southampton bossed and, if not for goalkeeper Asmir Begovic, it would have been much worse for the hosts. Two of Southampton's three goals were arguably a result of Chelsea shooting themselves in the foot, but the Saints not only forced the errors with their high-energy pressing, they had the killer instinct to punish them. The result cannot be debated, nor can the scoreline.

Chelsea's performance

'We want our captain back' were the words sung by Chelsea fans after the 2-1 Champions League defeat at Porto in midweek. They got their wish this evening, with John Terry restored to the first XI at the expense of Kurt Zouma, but the Blues' first-half display proved that their problems run much deeper. Bringing their skipper back may consolidate a defence which has leaked goals, but Terry's return did little to inspire an attack in short supply of them as Mourinho's men looked lifeless at the other end once again.

For the third successive game, Willian was on the scoresheet as his stunning free kick, from the tightest of angles, left Maarten Stekelenburg with no chance. But it papered over the cracks. Chelsea seldom threatened again in that half and it was their much-maligned defence which swiftly came into the picture as Southampton dominated.

Branislav Ivanovic, perhaps fortunate to have kept his place in the first XI after a trying few months, was even luckier when he dragged Virgil van Dijk to the floor inside the box. Not given. Ramires, preferred to Nemanja Matic in midfield, then tripped Mane inside the box. Not given. Poor officiating from referee Bobby Madley looked like preserving Chelsea's slender lead at half time, but Davis rifled home a deserved equaliser shortly before the break.

From there, Chelsea, the champions, collapsed. Gary Cahill and Terry were heavily at fault for the visitors' second on the hour mark, with the latter being spun by goalscorer Mane, before a loose pass from Cesar Azpilicueta led to the counter-attack which inspired the third and killer goal. This was the ever-present back four which helped them to the title last term. Tonight, they looked like strangers.

There was 18 minutes to play, but Chelsea were beaten. In fact, they were beaten when Davis equalised. There was an end-of-an-era feel over the way in which they collapsed in the second half. None of them looked like the players they were just a matter of months ago. Mourinho may be the 'special one', but coming back from this, with owner Roman Abramovich in attendance tonight, is the biggest test of his career. However, it remains to be seen if he will be given the chance to prove his nickname.

Southampton's performance

Before a ball was kicked tonight, Ronald Koeman claimed that Chelsea were there for the taking. If his pre-match words sounded like mere bravado then the way in which Southampton dominated the first half will have reiterated that the Dutchman was serious. Very serious. Despite falling behind after just 11 minutes, the Saints responded in a way that suggested they knew the game was far from over.

At the other end, Southampton were unlucky to miss out on two penalties, while Ryan Bertrand, on his return to Stamford Bridge, was denied by Begovic in the best chance of the half. It was a sign of things to come, as Pelle did brilliantly to chest the ball into the path of Davis, who rifled a crisp first-time volley past Begovic. It was nothing less than what they deserved and if the sincerity of Koeman's pre-match claims were still doubted, then his half-time substitution will have wiped away any such cynicism.

Koeman removed defensive midfielder Oriol Romeu - who was booked and conceded the foul which led to Willian's scorcher - for the more attack-minded James Ward-Prowse in a huge statement of intent. He smelled blood, and his players went about shedding more of it from their opponents in ruthless fashion. The warrior-like Mane single-handedly tormented Ivanovic, Cahill and Terry after the break, and he eventually saw his hard work rewarded when Pelle played him through for the visitors' second on 60 minutes. Again, utterly deserved.

There was only one moment of panic in their defence as Radamel Falcao got goal side of Jose Fonte before going to ground in the area when Stekelenburg raced out of his goal. The Dutch keeper did not make contact with the ball, but replays suggested that the Colombian was looking for the penalty and he was booked for diving.

While Chelsea were licking their wounds over that call, Southampton struck the lethal blow as Mane capitalised on a loose ball from Azpilicueta before driving at goal, playing in Pelle and the Italian finished well past Begovic. Beating Chelsea has arguably been devalued in recent weeks by virtue of the fact that this was their fifth defeat of the season, but few went about it better than Southampton tonight.

Sports Mole's man of the match

Sadio Mane: Simply put, there was just no better player on the field than Mane, who proved the scourge of title-winning defenders all evening. Scored one and set up one, but there was so much more to his performance and if Manchester United were interested in the summer, then the queue for his signature, and indeed his value, will be significantly bigger now.

Biggest gaffe

Take your pick. The Match of the Day pundits will be hard pressed for time if they were to analyse every Chelsea error tonight, but perhaps the most significant of the lot was Azpilicueta's hospital pass in the lead up to Southampton's third goal. At 2-1 down, Chelsea had a chance of salvaging a point at the very least, even if they were a million miles from their best, but Pelle's third killed them.

Referee performance

In truth, Madley did not have a brilliant game. At 1-0 down, Southampton had two solid penalty appeals rejected when fouls on Van Dijk and Mane went unpunished by the referee. In the second half, Madley was the centre of controversy again when he booked Falcao for diving after going down under a challenge from Stekelenburg - although that one was far less cut and dry.

What next?

Chelsea: With the international break next week, Chelsea are back in action on October 17 for the visit of Aston Villa.

Southampton: The Saints also return in two week's time when Koeman's side host Leicester City at St Mary's.