Dušan Tadić’s 18th minute penalty levelled the scores after Diego Costa had put the hosts in front with a close range header.
Tadić sent his spot kick down the middle of Thibaut Courtois’ net after Sadio Mané was fouled as he went to shoot with Saints delivering an impressive response to falling behind in the game.
A contest full of blood and thunder ensued for the remainder of a hard fought match, but ultimately, the spoils were shared once again between the two teams with Saints having also recorded a 1-1 draw with the Blues at St Mary’s in December.
Ronald Koeman had made a handful of changes to his starting eleven, with defender Toby Alderweireld back in the side for the first time since win over Manchester United in mid-January.
Shane Long and Dušan Tadić formed part of a new-look front line with Graziano Pellè making way, as the Italian frontman dropped to the bench. Eljero Elia missed out of the squad altogether through injury.
Chelsea got the game under way, and the hosts began at a high tempo as they showed no early signs of fatigue from their midweek exit from the Champions League.
A warning sign came on four minutes when Cesar Azpilicueta fired over from the right side after being put through by Willian from midfield.
And the sustained pressure moving forward paid off in the eleventh minute when good hold-up play from Eden Hazard led to the ball going out wide, where Branislav Ivanovic delivered an inviting cross for Diego Costa to cushion a header past Fraser Forster and open the scoring.
Despite that setback, Saints responded well, with Mané seeing a low shot from Tadić’s cross saved well by Courtois. Shortly after that, Tadić curled over from Victor Wanyama’s backflick inside the area with an effort which narrowly cleared the crossbar.
Koeman’s men would find a leveller though on 18 minutes from the penalty spot when Mané was brought down inside the box by Nemanja Matic
Tadić stepped up to score his second spot kick of the season by sending the ball down the middle of the goal for 1-1.
Saints upped the ante after finding a way back into the game, forcing Chelsea to make mistakes at the back as they tried to open up the Blues once more.
On 34 minutes, Steven Davis applied pressure in midfield and found Shane Long, who flicked the ball into Mané, and the Senegalese curled a shot towards the bottom corner, but Courtois wa able to hold on to it.
Chelsea came back into it towards the end of the half with Costa having the last chance of the opening 45 minutes when he headed over from Fabregas’s pass, leaving the teams unseparated heading into the interval.
Saints made a strong start to second half, taking the ball to Chelsea from kick-off, and almost catching the Blues cold when Steven Davis laid off a free-kick into the path of Tony Alderweireld, who smashed an effort towards the top corner which Courtois tipped over
The powerful opening from Saints prompted Jose Mourinho to make his first change of the game with Ramires introduced for Matic, and the Blues soon perked up again to prompt a battle of wits around the Southampton area.
The menacing presence of Diego Costa was well marshalled by Fonte, but the whole team would play its part in keeping Chelsea at bay, with Steven Davis notably making an impact at both end sof the pitch.
From Davis’s pass, Tadić almost created a moment of magic when he tricked his way through the Chelsea defence to get into the area, but elected pass to Long, whose shot was blocked by Azpilicueta.
After Chelsea successfully defended Davis’s free-kick, Saints showed their first hand on 71 minutes by bringing on James Ward-Prowse and Filip Djuričić in place of Davis and Tadić, with three points still looking very much up-for-grabs in the contest.
At the other end, having already denied Oscar from close range, Forster had to be alert again to prevent the Brazilian from a one-on-one position with a solid one handed save.
Forster clawed away a corner under pressure from Diego Costa before both teams made their final changes, with Remy and Cuadrado introduced for the hosts, while Pellè replaced Long for the final seven minutes.
A short burst forward from Mané almost opened up the Blues on the left, but the winger couldn’t steady himself to find the target, though the left flank continued to be a useful avenue for Saints to exploit.
Djuričić won a free-kick from that position soon after, but Chelsea soon threatened again at the other end as the hosts made a strong finish to the game.
Azpilicueta saw a low shot parried away by Forster, and from the resulting corner kick, first, Remy saw a shot blocked, and then John Terry fired wide, as Saints’ goal lived a slightly charmed life in the closing stages.
Another draw against the league leaders was confirmed after four minutes of stoppage time, which moved Saints back into the top six of the table.
Chelsea team: Thibaut Courtois, Branislav Ivanovic, Gary Cahill, John Terry (c), Cesar Azpilicueta, Nemanja Matic (Ramires 53), Cesc Fabregas, Oscar (Loic Remy 82), Willian (Juan Cuadrado 83), Eden Hazard, Diego Costa
Unused substitutes: Petr Cech, Filipe Luis, Kurt Zouma, Didier Drogba
Booked: Matic (18), Ivanovic (63), Cahill (68)
Goal: Costa (11)
Southampton team: Fraser Forster, Nathaniel Clyne, José Fonte (c), Toby Alderweireld, Ryan Bertrand, Victor Wanyama, Morgan Schneiderlin, Steven Davis (James Ward-Prowse 71), Sadio Mané, Dušan Tadić (Filip Djuričić 71), Shane Long (Graziano Pellè 83)
Unused substitutes: Kelvin Davis, Maya Yoshida, Florin Gardos, Matt Targett
Booked: Mané (29), Wanyama (63), Djuričić (82)
Goal: Tadić (18)
Referee: Mike Dean