Match ends, Chelsea 1, Southampton 1.
- Costa scores his 18th goal of the league season
- Tadic equalises from the spot
- Ivanovic claims for a penalty waved away
- Forster makes several brilliant saves
Chelsea moved six points clear at the top of the Premier League after drawing with Southampton in a superb contest at Stamford Bridge.
Diego Costa gave Chelsea the lead with a header before Dusan Tadic equalised from the spot after Nemanja Matic had fouled forward Sadio Mane.
Southampton keeper Fraser Forster made a series of great saves to deny Oscar and Eden Hazard.
In the closing moments he made a point-blank block from substitute Loic Remy.
Chelsea still have a game in hand on second-placed Manchester City, while Southampton moved into sixth above Tottenham, who later lost 3-0 to Manchester United.
The Blues' remaining major hurdles are Manchester United and Liverpool at home and Arsenal away, but some bookies still have them as 10-1 odds-on favourites for the Premier League, such is the belief that Jose Mourinho will claim his third title in England.
With the League Cup already in the bag, this looks set to be a very successful season for the Portuguese, marred slightly by the blip in midweek when Chelsea were knocked out of the Champions League by Paris St-Germain after drawing at Stamford Bridge on Wednesday.
Mourinho gave 10 of the 11 players that started that match the chance to redeem themselves against the Saints, but the first-half display was poor.
It began well for the home side when the unmarked Costa, who had not scored since January, got on the end of a delightful Ivanovic ball to head in his 18th of the campaign.
However, Southampton were level eight minutes later. Mane, who was a constant menace for centre-backs Gary Cahill and John Terry, found himself sandwiched by Ivanovic and Matic in the penalty area.
Referee Mike Dean awarded a penalty and showed an incensed Matic a yellow card. Tadic was left to despatch the spot-kick.
The Serb was close to adding a second when his angled drive was brilliantly saved by Thibaut Courtois. The Belgian keeper then came to his side's rescue again when his one-handed stop kept out Toby Alderweireld's free-kick.
Chelsea did have a shout for a penalty at 1-1 when Ivanovic's heel appeared to be clipped by Tadic, but the referee waved away the player's appeal.
Mourinho's side needed some inspiration and whatever he said at half-time appeared to do the trick.
The Portuguese brought on Ramires to replace Matic, which gave Chelsea more pace and industry in midfield.
They suddenly looked a different proposition. If only they had not come up against Forster, who was in sparkling form.
The Southampton stopper staked a very strong claim for the England number one jersey with blocks to twice deny Oscar, Eden Hazard and Cesar Azpilicueta, who was agonisingly close to scoring his first league goal for the club.
- 2IvanovicBooked at 63mins
- 24CahillBooked at 68mins
- 21MaticBooked at 18minsSubstituted forSantos do Nascimentoat 53'minutes
- 22WillianSubstituted forJu Cuadradoat 83'minutes
- 8OscarSubstituted forRemyat 82'minutes
- 10E Hazard
- 19Diego Costa
- 3Filipe Luís
- 7Santos do Nascimento
- 23Ju Cuadrado
- 6José Fonte
- 12WanyamaBooked at 63mins
- 10ManéBooked at 29mins
- 8DavisSubstituted forWard-Prowseat 71'minutes
- 11TadicSubstituted forDjuricicat 71'minutesBooked at 82mins
- 7LongSubstituted forPellèat 83'minutes
- Mike Dean
- Shots on Target
Second Half ends, Chelsea 1, Southampton 1.
Offside, Southampton. Sadio Mané tries a through ball, but Graziano Pellè is caught offside.
Branislav Ivanovic (Chelsea) wins a free kick in the defensive half.
Foul by Graziano Pellè (Southampton).
Attempt missed. John Terry (Chelsea) left footed shot from the centre of the box misses to the right following a corner.
Attempt blocked. John Terry (Chelsea) right footed shot from the centre of the box is blocked.
Attempt saved. Loïc Remy (Chelsea) right footed shot from the centre of the box is saved in the centre of the goal. Assisted by Gary Cahill with a headed pass.
Corner, Chelsea. Conceded by Fraser Forster.
Attempt saved. César Azpilicueta (Chelsea) right footed shot from outside the box is saved in the bottom left corner. Assisted by Eden Hazard.
Foul by Ramires (Chelsea).
Filip Djuricic (Southampton) wins a free kick on the left wing.
Attempt blocked. James Ward-Prowse (Southampton) left footed shot from the centre of the box is blocked. Assisted by Filip Djuricic.
Attempt missed. Juan Cuadrado (Chelsea) left footed shot from the right side of the box is close, but misses to the right. Assisted by Cesc Fàbregas.
Corner, Chelsea. Conceded by Graziano Pellè.
Corner, Chelsea. Conceded by Toby Alderweireld.
Attempt missed. Sadio Mané (Southampton) left footed shot from the left side of the box is high and wide to the left. Assisted by Morgan Schneiderlin.
Substitution, Chelsea. Juan Cuadrado replaces Willian because of an injury.
Substitution, Southampton. Graziano Pellè replaces Shane Long.
Filip Djuricic (Southampton) is shown the yellow card for a bad foul.