Last Updated: 01/12/13 6:08pm
A powerful second-half showing from Chelsea saw Southampton concede three goals in the Premier League for the first time this season. Saints were gifted the lead after just 12 second when Michael Essien's woeful backpass let in Jay Rodriguez and they were good value for that lead at the break. But Chelsea moved through the gears in the second period with goal from Gary Cahil, John Terry in his 400th Premier League game and Demba Ba taking them up into second spot in the table.
Saints force a corner that Osvaldo plays short but then loses it to Ivanovic with a sea of red shirts waiting for a cross.
It's the first time Southampton have conceded three goals in the Premier League this season and you just would not have predicted it would happen at half-time when they were leading and so much in control.
Ramires gets in a cross that is met first time by Ba as he slides in and the ball finds the corner of the net.
Some fans are heading for the exits which will let the players know there is not long to go so will be there be late drama?
Osvaldo tries a shot which loops just wide of Cech's goal and the home keeper dod not look too confident with that.
Ba is caught offside and after so many of them in the opening 45 minutes, I think this is the first one of the second period!
Gazzaniga races off his line to gather the ball ahead of Ba after Mata's pass threatened to put him clear.
Osvaldo leads a rare Saints attack and lays it off to Lambert on the edge of the box, but Cahill blocks his shot and Rodrirguez loses the ball to Lampard.
The hosts are looking for a third and again keeper Gazzaniga claims the ball just in time with Ba lurking behind him.
It's been quite a turnaround in the second period after Southampton had looked so assured and solid at the back.
Southampton force a corner which Davis takes but Wanyama and Fonte both have efforts blocked inside a packed 18-yard area.
Lampard sets Ba clear with a great long pass but the striker shakes off his marker but slips the ball wide of the far post.
Torres rises highest to flick on a long throw but it's that man Lovren who is once again on hand to clear.
A break in play with Schneiderlin needing treatment and it looks as though he will also have to come off.
Lampard picks out Cahill in the area with the free-kick and he heads down for Torres but he can't get it under control and Lovren stabs it away.
Mata's corner is headed out to Lampard on the edge of the box and he volleys a pass back outy to Mata whose cross is met by a glancing header from Terry which finds the top corner to mark his 400th Premier League appearance in style.
Lovren then has to be alert to get the ball away from Hazard as he attempts to get on the end of a through ball from Torres.
Lovren uses his strength to ease Ba off the ball and quite rightly claims for a free kick are waved away.
Boruc is unable to carry and is replaced by Paulo Gazzaniga who has not played a league game this season.
Boruc needs treatment after colliding with the post in his efforts to keep out the flick from Ramires.
Hazard's corner is met by Terry who heads goalwards and Boruc does well to keep out a touch from Ramiers but the ball breaks to Cahill who heads in his first goal of 2013 from close range.
Ramieres brings down Shaw and it should be a booking, but it isn't and Ward-Prowse wastes the free kick.
Wanyama goes through the back of Torres but the offside flag is up and maybe that has spared him a booking.
"I would love to know what Jose Mourinho sees in Ivanovic as a right back as he is constantly caught out of position defensively, lacks the pace to keep up with good wingers and isn't able to put in a good delivery when he does get the ball in forward positions. Every game Chelsea play with people like Ramires, Lampard and Essien in holding roles makes Van Ginkel look even better. I cannot wait til the birthday boy gets back fit," says Karl Beake.
"Another substandard performance from Chelsea. The team has no fight, no drive, no leadership and no direction. Too many players of the same type, all wannabe number 10's and all too light weight. Chelsea have lost the air of invincibility at home and are always there for the taking," says Chelsea fan Peter from London.
Michael Essien's woeful back pass has gifted Southampton a half-time lead at Stamford Bridge. Jay Rodriguez was the grateful recipient as he stroked the ball home with just 12 seconds on the clock. Saints keeper Artur Boruc made a superb one-handed save to keep out a Fernando Torres header, but overall Chelsea have lacked a cutting edge in the final third and have consistently fallen into a well-organised offside trap.
How crucial could that save from Boruc be? It had goal written all over it until the Pole thrust out his hand to stop it.
Hazard and Mata combine well to get in a cross which is met by a header from Torres that Boruc keeps out with a brilliant one-handed save going to his right before the ball is hacked clear.
Torres does superbly to get in a cross when under pressure from two defenders and it is met by the head of Oscar but Boruc makes a fine save to his left.
Ward-Prowse cuts the ball back for Adam Lallana on the edge of the box but he scuffs a low shot well wide.
wanyama is first up and limps gingerly over the touchkline, followdd by Oscar so it looks as though both will continue.
A break in play with Wanyama and Oscar both down after seperate challenges and both seem to be in plenty of pain.
There is a very subdued atmosphere in the ground which is a sign of how well the visitors are playing.
A bit of a lull in the game which will suit Saints who are knocking the ball around with confidence.
Essien gives Torres a ball to chase but Lovren is across and although the ball bounces up off him, Boruc gathers.
Boruc - not one the tallest keepers in the Premier League - does well to claim a dangerous Hazard free-kick in a crowded box.
You would think that in the course of 90 minutes Chelsea will spring this offside trap, but Saints are so well-drilled and organised so maybe they can just keep adding to Chelsea's growing frustration.
Good move by Chelsea ends with Ramires slipping the ball to Mata whose shot is parried by Boruc - but again the offside flag is up.
Azpilicueta concedes a corner as he stops Clyne. Ward-Prowse takes it and again it is headed clear at the near post.
Torres turns well in the box and there are penalty appeals but it was another great tackle by Lovren.
Hazard's clever flick plays in the over-lapping Azpilicueta and his cross is met by Oscar but there is not enough power in the header to trouble Borus.
Hazard takes a Chelsea corner that drops to Oscar 20 yards out and Boruc awkwardly parries his fierce shot but again the offside flag goes up.
Saints are using such a high line when they defend and Chelsea have not managed to counter it as yet.
Luke Shaw bombs forward down the Saints left but Branislav Ivanovic shrugs him off the ball and claims for a free-kick are turned down by referee Michael Oliver.
Saints keeper Artur Boruc is put under pressure by a strongly-hit backpass which he slices out for a throw but his side quickly win it back.
Southampton have been comfortable so far and there is already some discontent among the home supporters.
A break in play as Daniel Osvaldo needs treatment, but walks off the field without too much trouble and will be able to carry on.
Torres runs at the heart of the Saints defence but is stopped by a fine tackle on the edge of the box by Dejan Lovren.
Essien has had a couple of decent touches since his early blooper and that will help his confidence.
Hazard is tripped in the centre circle and there are moans from the home fans as their side is denied taking the resulting free-kick quickly by the referee.
Chelsea have responded in positive fashion before Cesar Azpilicueta loses out to Nathniel Clyne and Saints have a throw.
Southampton play the ball forward from the kick-off and Essien's attempted backpass is woefuul, straight to Rodriguez 16 yards out and he tucks the ball past Petr Cech.
Chelsea fan Guy says: "It's a must-win for our boys today. There's plenty of flare in the midfield so let's do a job and show everyone we're still up for the title!"
"Would like to see Mourinho try his old formation - the diamond one - with Lampard In his best position playing behind the striker," says Phil from Hull.
"Great to see Mata in the lineup - I think he'll be the key to Chelsea's success this afternoon whilst trying to prove his worth. A little less support and more defence from further back without Lampard and Southampton to come in strong but I reckon another win on the record sheet for Mourinho," says Tim Coleman.
Our colleagues at Sky Bet have Chelsea very warm 4/7 favourites to win the game, with Saints 5/1 and the drawn on offer at 16/5. Juan Mata is 8/1 to get the first goal, with a Blues 3-1 success a 12/1 chance.
Will Masters say: "Should be an interesting game today, Southampton looking good and Chelsea need to bounce back from that midweek setback. I am predicting a 2-0 Chelsea win though as there seems to be too much quality in the squad to lose or draw at home."
"Southampton have taken me by surprise this season and it would be a magnificent achievement for them if they came here and stunned Chelsea, but I can't see them generating another shock this afternoon as the Blues never seem to perform poorly in front of their home crowd nowadays," says Chris Green from Huddersfield.
Juan Mata starts as one of four changes as Chelsea take on Southampton looking to cut the seven-point deficit to Barclays Premier League leaders Arsenal. Playmaker Mata, midfielder Michael Essien, striker Fernando Torres and forward Eden Hazard begin the first of nine December games for the Blues, who lost 1-0 to Basle on Tuesday night and were fortunate to scramble a draw from their most recent home match against West Brom. John Obi Mikel, Frank Lampard, Willian and the injured Samuel Eto'o are the players who make way against a Southampton side showing two changes from the side which began last weekend's loss at Arsenal, with Dejan Lovren and Dani Osvaldo replacing Jos Hooiveld and Rickie Lambert.
The teams have arrived nice and early and are as follows - Chelsea: Cech, Ivanovic, Cahill, Terry, Azpilicueta, Essien, Ramires, Hazard, Mata, Oscar, Torres. Subs: Cole, Lampard, Mikel, Schurrle, Ba, Willian, Schwarzer. Southampton: Boruc, Clyne, Fonte, Lovren, Shaw, Wanyama, Schneiderlin, Ward-Prowse, Lallana, Rodriguez, Osvaldo. Subs: Yoshida, Lambert, Steven Davis, Cork, Chambers, Gazzaniga, Hooiveld. Referee: Michael Oliver (Northumberland)