Ronald Koeman's men took an early lead through Sadio Mane but an equaliser from the Belgian saw the two sides share the spoils, despite Morgan Schneiderlin's second half red card
Jose Mourinho's men failed to hit their usual impeccable standards on the south coast, with Southampton displaying their top-four credentials in a battling display.
|VIEW FROM ST MARY'S STADIUM
|By Liam Twomey
Chelsea will go into 2015 on top of the Premier League, but Jose Mourinho will be a frustrated man. Southampton showcased their quality and their grit to take two points off the leaders, and perhaps signs of festive fatigue could be seen in the Blues' failure to find a late winner despite waves of late pressure.
Cesc Fabregas and Eden Hazard were again fantastic, combining for the goal that got Chelsea back into this match, but Diego Costa was well marshalled by the superb Jose Fonte and Toby Alderweireld and looks in need of a few days' rest if he is to be back at his rampaging best against Tottenham on New Years' Day. A win over their London rivals is an absolute must now in the battle to stay ahead of an ominous-looking Manchester City.
Southampton are still waiting for their statement win against a member of the Premier League elite, but this result was excellent in itself and it seems clear they will be fighting it out for at least a top six position at the end of the season.
However, a moment of brilliance from Eden Hazard shortly before the break levelled proceedings, as he curled home his seventh league goal of the campaign.
Chelsea pushed hard for a winner after the break and felt hard done by when Cesc Fabregas was booked for simulation despite being tripped by Matt Targett.
But Mourinho's side had to settle for a point - despite an 88th-minute red card for Southampton's Morgan Schneiderlin.
A draw ensures Chelsea will top the pile going into 2015, while Southampton hit back at their sceptics after recent defeats to Manchester City, Arsenal and Manchester United.
Dusan Tadic, one of four Southampton changes from the 3-1 beating of Crystal Palace on Boxing Day, tested the water early with a shot from distance that went well wide.
The Serbia winger then played an influential role as the hosts moved ahead in the 16th minute.
His expertly dinked through ball caught Terry flat-footed and the Chelsea skipper was left trailing in Mane's wake as the Senegal winger sprung the offside trap and kept his cool to lift the ball over Courtois.
Chelsea made just three alterations to the team that beat West Ham on Friday and did not take long to showcase their talent, dominating the majority of possession, but they were uncharacteristically wasteful in the final third.
However, the visitors restored parity on the stroke of half-time with a fine finish from Hazard.
Creator-in-chief Fabregas showed great vision to play a delicate chip into the path of the Belgian in the left channel, and he promptly cut inside international team-mate Toby Alderweireld before bending a fierce shot into the far corner.
Fabregas was again involved 10 minutes after the break when he was tripped inside the penalty area by teenage full-back Targett – making his first league start in place of Chelsea loanee Ryan Bertrand – but referee Anthony Taylor deemed it a dive and booked the incredulous Spaniard.
The visitors continued to press and Fabregas once again teed up Hazard on the hour but this time he flashed wide of the right-hand post, while Didier Drogba was introduced to add muscle to Chelsea's attack.
However, for all the visitors' pressure a clear-cut opportunity never materialised and even when Schneiderlin received a second yellow card and subsequent red for hacking down Fabregras on the half-way line Chelsea could not find a way through, missing the chance to keep daylight between themselves and Manchester City.