Chelsea suffered another case of the Stamford Bridge stutters as they threw away a two-goal lead to Southampton, who snatched a 2-2 draw.
Demba Ba, with his 14th Barclays Premier League strike of the season, and Eden Hazard had put Chelsea in control and they seemed to be cruising to a first home victory since before Christmas. But Rickie Lambert pulled Southampton back into the game with a header moments after being sent on and Jason Puncheon equalised with a brilliant volley.
Since their 8-0 rout of Aston Villa on December 23, Chelsea have lost at home to QPR and Swansea and have now drawn with the relegation-battling Saints.
There were some nice touches from the Blues early on but they lacked any real penetration, with Oscar shooting wide after a neat build-up from Hazard, Ba and Juan Mata.
Southampton engineered a chance for Puncheon, who rose above Ashley Cole but he only managed a soft header back across goal before Chelsea took a grip on the game.
Frank Lampard played a key role and Ba, who had marked his Chelsea debut with two goals in the FA Cup tie, finished. The Chelsea captain beat Luke Shaw before laying the ball back for Cesar Azpilicueta to curl the cross in. Oscar and Jos Hooiveld both went for the header and the ball deflected up for Ba, who executed an acrobatic volley to beat Artur Boruc.
Chelsea survived a scare when Jay Rodriguez pulled a long-ball out of the air with a delightful first touch and teed up Steven Davies, who side-footed his shot wide from the edge of the box. That scare jolted Chelsea into action. Ba headed back to Lampard, who lifted the ball towards Hazard and Oscar, who got in a muddle but still forced Boruc to tip it round the post.
And when Southampton made a hash of clearing their lines, Chelsea pounced for the second. Ramires rifled a shot off the post but Hazard followed up to drill a left-footed shot past Boruc.
The second half started in stalemate. But the onus was on the visitors and manager Nigel Adkins threw on Lambert for Rodriguez after 55 minutes. Three minutes later he had scored. Nathaniel Clyne escaped the attentions of Hazard and swung in a deep cross for Lambert, who found space to head past Petr Cech for his 10th league goal of the season.
And then, with 15 minutes remaining, Southampton equalised. Shaw charged 50 yards down the left and pulled the cross back for Puncheon, who teed the ball up with his first touch and powered a volley past Cech with his second.