text: Demba Ba leapt to put the Blues ahead with a deflected shot and Eden Hazard added a second before the break, following up when Ramires hit the bar.
  Saints created little until Rickie Lambert came off the bench to head home Nathaniel Clyne's cross.
  Jason Puncheon levelled when he smashed home Luke Shaw's cross and Southampton left with an unlikely draw.
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  Chelsea have now won only one out of six domestic games at Stamford Bridge under Benitez and, for the third successive home game, boos rang out at the final whistle.
  It was easy to understand the home fans' frustrations. This was a game that they seemingly had wrapped up at half-time despite missing several chances but they were rattled by Lambert's introduction and instant impact.
  Ba could have made sure of the points when he volleyed over in the second half but sloppy defending gave Puncheon room for his explosive finish, which leaves Chelsea 13 points behind leaders Manchester United, with 16 games left.
  Home: P6 W1 D3 L2 F10 A5
  Away: P7 W6 D0 L1 F21 A7
  Results in Premier League, FA Cup and Capital One Cup, not including World Club Championship or Champions League.
  It was only the third time in 90 home matches in the Premier League era that Chelsea had surrendered a 2-0 half-time lead, a slip particularly ill-timed from Benitez's point of view considering the news about Pep Guardiola earlier in the day.
  The announcement that the long-term Chelsea managerial target is to take charge of Bayern Munich next summer might have been bad news for Blues owner Roman Abramovich, but surely represents a window of opportunity for his interim boss.
  If Benitez is to stay for longer than the end of this campaign, then results will arguably matter more than the opinion of the fans who have opposed his appointment from the start.
  At the moment, both are going against him on home turf. Benitez has claimed this is down to the tactics of visiting teams rather than a reaction to the often abusive atmosphere but against Southampton it was poor finishing - and defending - that was to blame.
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  Chelsea were comfortable at the break, taking the lead through Ba's instinctive finish from Cesar Azpilicueta's cross and doubling it when Hazard impressively despatched a bouncing ball from the edge of the area after Ramires had struck the bar.
  But the home side were given a rude awakening when Saints' top scorer Lambert, left on the bench while his side looked to defend deep and counter-attack before half-time, was summoned for a rescue mission.
  It took Lambert, the leading English scorer in the top division, precisely two minutes and 47 seconds to announce his arrival in the game, powering home his header for his 10th goal of a productive campaign.
  Chelsea could still have made the points safe, with Ba missing the target completely after he ran on to Juan Mata's superbly clipped pass, but it was Saints who had the last word as they extended their unbeaten league run to five games.
  Shaw raided forward down the left flank and his cross was allowed to bounce across the edge of the area, where it was met by Puncheon to take a touch and fire a superb strike past the helpless Cech.
  Chelsea interim manager Rafael Benitez: "We should have won.
  "We didn't take our chances when we had them. We had situations where we could score. We didn't and they broke on a counter-attack. We gave them hope they could score and they did it.
  "I was talking to the team at half-time, trying to say 'we have to score a third goal'.
  "I think for us we cannot be happy drawing at home. I am disappointed.
  Southampton manager Nigel Adkins: "We came with a game-plan to be compact and frustrate the opposition.
  "It was a big call to leave Rickie Lambert out but we wanted to make sure we were in the game.
  "At half-time it was 2-0 and I said, 'stick to the game-plan'. If we had gone and chased it there was every chance we could have ended up with a scoreline like Aston Villa, who conceded eight here.
  "We stuck at it. Rickie came on and scored the goal and what a fantastic goal it was for the second one.
  Full Time   The referee brings the game to a close.
  The referee blows for offside against Ashley Cole.  Artur Boruc restarts play with the free kick.
  A cross is delivered by Fernando Torres.
  The ball is delivered by Juan Mata, clearance by Maya Yoshida.
  The ball is sent over by David Luiz, Jos Hooiveld manages to make a clearance.
  The ball is delivered by David Luiz.
  Free kick awarded for a foul by Nascimento Ramires on Gaston Ramirez. Gaston Ramirez produces a shot on goal direct from the free kick, blocked by Fernando Torres.
  Juan Mata crosses the ball, Jos Hooiveld makes a clearance.
  Luke Shaw challenges Fernando Torres unfairly and gives away a free kick. Free kick taken by Juan Mata.
  Rickie Lambert concedes a free kick for a foul on David Luiz. Petr Cech takes the free kick.
  Free kick awarded for an unfair challenge on Gaston Ramirez by Fernando Torres. Direct free kick taken by Jos Hooiveld.
  Gaston Ramirez concedes a free kick for a foul on Emboaba Oscar. Petr Cech restarts play with the free kick.
  David Luiz crosses the ball, clearance made by Luke Shaw.
  Fernando Torres has an effort at goal from the edge of the box that misses to the right of the target.
  The assistant referee flags for offside against Demba Ba. Free kick taken by Artur Boruc.
  Jos Hooiveld crosses the ball in from the free kick, comfortable save by Petr Cech.
  Booking      David Luiz booked for unsporting behaviour.
  Unfair challenge on Gaston Ramirez by David Luiz results in a free kick.
  Fernando Torres takes a shot. Blocked by Jos Hooiveld.
  Demba Ba produces a volleyed right-footed shot from 18 yards.
  Gaston Ramirez gives away a free kick for an unfair challenge on Nascimento Ramires. Juan Mata takes the direct free kick.
  Corner from the right by-line taken by Juan Mata, Jos Hooiveld makes a clearance.
  Foul by Fernando Torres on Jack Cork, free kick awarded. Jos Hooiveld restarts play with the free kick.
  Substitution      Frank Lampard goes off and Fernando Torres comes on.
  The ball is swung over by Luke Shaw, David Luiz manages to make a clearance.
  Free kick awarded for an unfair challenge on Jason Puncheon by David Luiz. Gaston Ramirez crosses the ball in from the free kick, clearance made by Nascimento Ramires.
  Nascimento Ramires fouled by Gaston Ramirez, the ref awards a free kick. Shot comes in from David Luiz from the free kick.
  Assist by Gaston Ramirez.
  Goal!  - Jason Puncheon -    Chelsea 2 - 2 Southamp'n        Jason Puncheon scores a goal from just inside the penalty area to the top left corner of the goal. Chelsea 2-2 Southampton.
  Direct free kick taken by Ashley Cole.
  Substitution      Guly Do Prado goes off and Gaston Ramirez comes on.
  Richard Chaplow concedes a free kick for a foul on Eden Hazard.
  Corner taken by Jason Puncheon, Petr Cech makes a comfortable save.
  Rickie Lambert takes a shot. David Luiz gets a block in.
  Unfair challenge on Juan Mata by Maya Yoshida results in a free kick. Strike on goal comes in from Frank Lampard from the free kick.
  The ball is crossed by Jason Puncheon, clearance made by Gary Cahill.
  The referee blows for offside. Indirect free kick taken by David Luiz.
  Shot from deep inside the area by Demba Ba clears the crossbar.
  Foul by Morgan Schneiderlin on Frank Lampard, free kick awarded. Free kick taken by Nascimento Ramires.
  Direct free kick taken by Maya Yoshida.
  Substitution      Richard Chaplow replaces Steven Davis.
  Emboaba Oscar gives away a free kick for an unfair challenge on Jason Puncheon.
  Ashley Cole produces a drilled left-footed shot from 12 yards. Jason Puncheon gets a block in.
  Jack Cork challenges Emboaba Oscar unfairly and gives away a free kick. Direct free kick taken by Emboaba Oscar.
  Ashley Cole sends in a cross.
  The ball is crossed by Nathaniel Clyne.
  Nathaniel Clyne delivers the ball, Cesar Azpilicueta makes a clearance.
  Free kick awarded for a foul by Rickie Lambert on David Luiz. Free kick taken by David Luiz.
  Effort on goal by Emboaba Oscar from just inside the penalty area goes over the target.
  The assist for the goal came from Nathaniel Clyne.
  Goal!  - Rickie Lambert -    Chelsea 2 - 1 Southamp'n        Rickie Lambert finds the net with a headed goal from inside the box. Chelsea 2-1 Southampton.
  Nathaniel Clyne sends in a cross,
  Free kick taken by Artur Boruc.
  Substitution      Jay Rodriguez goes off and Rickie Lambert comes on.
  The referee blows for offside.
  Emboaba Oscar challenges Morgan Schneiderlin unfairly and gives away a free kick. Guly Do Prado crosses the ball in from the free kick.
  Corner taken left-footed by Jason Puncheon, Cesar Azpilicueta makes a clearance.
  The assistant referee flags for offside against Jay Rodriguez. David Luiz takes the direct free kick.
  Demba Ba sends in a cross, Artur Boruc makes a comfortable save.
  Free kick awarded for a foul by Frank Lampard on Jack Cork. Maya Yoshida takes the direct free kick.
  Ashley Cole takes a shot. Comfortable save by Artur Boruc.
  The game restarts for the second half.
  Half Time    The whistle is blown to end the first half.
  Nascimento Ramires takes a shot from just outaide the penalty area and strikes the post.
  Assist on the goal came from Nascimento Ramires.
  Goal!  - Eden Hazard -    Chelsea 2 - 0 Southamp'n        A goal is scored by Eden Hazard from just inside the penalty area to the top right corner of the goal. Chelsea 2-0 Southampton.
  Juan Mata takes a short corner.
  Juan Mata sends in a cross.
  Guly Do Prado concedes a free kick for a foul on Juan Mata. Direct free kick taken by Juan Mata.
  Effort from the edge of the box by Frank Lampard goes wide of the left-hand upright.
  Nascimento Ramires takes a shot. Maya Yoshida gets a block in.
  Shot by Frank Lampard. Luke Shaw gets a block in.
  Juan Mata delivers a pass corner to short, Maya Yoshida manages to make a clearance.
  Effort from the edge of the box by Steven Davis goes wide of the left-hand upright.
  A cross is delivered by Jack Cork, David Luiz manages to make a clearance.
  The ball is delivered by Luke Shaw, Nascimento Ramires manages to make a clearance.
  Corner taken right-footed by Guly Do Prado from the left by-line to the near post, Frank Lampard makes a clearance.
  Free kick awarded for a foul by Demba Ba on Jack Cork. Free kick crossed left-footed by Jason Puncheon from right channel, clearance made by Gary Cahill.
  Assist on the goal came from Emboaba Oscar.
  Goal!  - Demba Ba -    Chelsea 1 - 0 Southamp'n        Demba Ba finds the net with a goal from inside the penalty box to the bottom right corner of the goal. Chelsea 1-0 Southampton.
  Cesar Azpilicueta delivers the ball,
  The ball is swung over by Cesar Azpilicueta, Maya Yoshida manages to make a clearance.
  The referee gives a free kick against Demba Ba for handball. Free kick taken by Artur Boruc.
  Demba Ba takes a shot. Save by Artur Boruc.
  The assistant referee flags for offside against Jay Rodriguez. David Luiz restarts play with the free kick.
  Guly Do Prado delivers the ball, Header by Jason Puncheon from deep inside the penalty area misses to the left of the target.
  Nascimento Ramires gives away a free kick for an unfair challenge on Morgan Schneiderlin. Direct free kick taken by Jos Hooiveld.
  Effort on goal by Cesar Azpilicueta from outside the box goes harmlessly over the bar.
  The ball is sent over by Juan Mata.
  Juan Mata takes the outswinging corner, clearance by Jay Rodriguez.
  Demba Ba delivers the ball.
  Effort from the edge of the box by Emboaba Oscar goes wide of the left-hand post.
  Centre by Luke Shaw, blocked by Emboaba Oscar.
  Nathaniel Clyne produces a cross, clearance made by Ashley Cole.
  Effort from outside the penalty area by Jay Rodriguez goes wide left of the goal.
  The referee gets the game underway.
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target: Chelsea's poor home record under Rafael Benitez continued as Southampton fought back from 2-0 down to snatch a point.