Chelsea’s disappointing start to the defence of their Barclays Premier League title continued as they were stunned 3-1 by a rampant Southampton side at Stamford Bridge.
Jose Mourinho’s side took the lead through Willian’s free-kick, but Steven Davis levelled for Southampton just before half-time.
Chelsea’s claims for a penalty on Radamel Falcao by Maarten Stekelenburg in the second half were denied. And shortly afterwards Sadio Mane put the Saints in front after capitalising on an error from the returning John Terry. Graziano Pelle, who had set up the two previous goals, sealed the win in the 72nd minute.
The champions have taken eight points from as many matches after conceding three times in a home league match for the first time ever under Mourinho, while Southampton have won three consecutive matches and scored 12 goals in the process.
Mourinho had said before the match he would continue to rotate his side as he searches for a winning formula and did that with four changes as Falcao, Eden Hazard, Oscar and Terry were selected.
Former Chelsea midfielder Oriol Romeu started in place of James Ward-Prowse in the only alteration made by Southampton manager Ronald Koeman.
Chelsea took the lead in the 10th minute after Romeu had been booked for a foul on Hazard out wide. Willian stepped up and his 30-yard delivery found the top far corner after bouncing off a post. It was unclear if the attempt was deliberate, but the Brazilian celebrated scoring for the fourth match in a row.
Virgil van Dijk’s penalty appeal for a foul by Branislav Ivanovic at a corner was rejected, before Davis lashed an effort wide as Southampton attempted to respond.
At the other end, Stekelenburg saved Oscar’s curling effort after the Brazilian had combined well with Cesc Fabregas in a congested penalty area.
The Saints appealed for a spot-kick again when Mane went down in the box under Ramires’ challenge but were denied by referee Robert Madley.
Southampton were the better side as the first half drew to a close and Mane showed great work to dribble infield and send a pinpoint pass to Ryan Bertrand, but Asmir Begovic narrowed the angle and denied the left-back a goal against his former club.
The equaliser arrived one minute before half-time. A long pass from defence was chested down by Pelle on the edge of the box and Davis stepped up to hit a low shot into the bottom corner.
Both sides made changes at the break, with Nemanja Matic replacing Ramires and Ward-Prowse coming on for Romeu.
Within minutes of the restart, a sweeping Southampton passing move almost resulted in a goal, but Begovic did well to repel Mane’s effort at close-range after Dusan Tadic’s square pass.
Chelsea were struggling to generate clear-cut opportunities but claimed for a penalty when Falcao outmuscled Jose Fonte and went down in the box as he attempted to round Stekelenburg. Instead the Colombian received a booking for simulation.
A few minutes later Southampton led. After Gary Cahill had given away possession, Pelle slipped through a pass which Terry misjudged, allowing Mane to race through on goal. Begovic got something on the ball in his attempt to save but not enough to prevent it crossing the line.
There was more woe for Chelsea on 72 minutes. This time it was Hazard who gave away the ball and Mane led a swift counter-attack before setting up Pelle down the right channel to convert with a lethal finish into the far corner.
A crucial block from Terry denied Southampton a fourth after Mane won a battle of strength with Cahill down the left and brilliantly set up Tadic.
Chelsea almost had a goal back when Stekelenburg allowed substitute Pedro the opportunity to shoot, but the winger was just off target.
Chelsea manager Jose Mourinho: “Three months ago we were all together in the bus with the cup, so I think it’s time for all of us to be together now in the bottom of the league. I think December, January, February, we are top four. To be champion will be very, very difficult.
“I think top four is completely do-able. When you are in such a bad start, if at the end of the season you finish top four, it’s because you kept the balance in a difficult season.”
Southampton manager Ronald Koeman: “We had a difficult start to the game but we came back and we made it 1-1 with a great goal. The difference was how we came out of the dressing room, pressed Chelsea and had fantastic movement. In my opinion, we totally deserve three points.”