Brighton opened the scoring in the 29th minute after good work to get the ball through Southampton's midfield toward right-back Tariq Lamptey, who crossed from the flank to the penalty area where hid delivery was met by a diving Kaoru Mitoma.
Flynn Downes brought the Saints level in the 59th minute after he smashed the ball home just in front of the penalty spot following chaotic defending from Brighton.
Southampton's Cameron Archer thought he had scored his side's second in the 67th minute after finishing from close range following a cross across the box by Ryan Fraser, but Adam Armstrong was adjudged to have been interfering with play from an offside position as the cross came in.
The result means that Brighton have leapfrogged Manchester City and end the night in second place with 23 points, and are unbeaten in their last three league games.
As for Southampton, they now have five points but are still last in the Premier League and are three points from safety while having played 13 matches, one more than all of their relegation rivals.
While Saints fans might be critical of Yukinari Sugawara, who failed to adequately track Mitoma's burst into the box for his opener, Brighton as a whole deserve great credit for overloading Southampton's right side and working through a compact midfield to give Lamptey the space he needed in order to send in a cross toward the goalscorer.
The equaliser came about after a well-structured attack down the left saw Southampton strike twice from inside the box at Bart Verbruggen's goal, and despite Downes arguably being fortunate to have received the ball in such a favourable position, nobody can fault his finish into the bottom-right corner.
Though it could be argued that Armstrong was indeed interfering with play considering he forced Brighton's defence into action, the decision seems harsh given the ball would have likely reached Archer at the back post regardless of his Armstrong's positioning.
BRIGHTON & HOVE ALBION VS. SOUTHAMPTON HIGHLIGHTS
Kaoru Mitoma goal vs. Southampton (29th min, Brighton & Hove Albion 1-0 Southampton)
Brighton work the ball through midfield and toward Tariq Lamptey on the right flank in Southampton's half, and the right-back whips an exceptional cross into the box near the penalty spot where Kaoru Mitoma meets his bouncing delivery with a header into the left side of the net!
Flynn Downes goal vs. Southampton (59th min, Brighton & Hove Albion 1-1 Southampton)
Southampton attack down Brighton's left and work the ball to Adam Armstrong in the box but his shot is blocked, as is his second effort, but Downes makes no mistake when he smashes home from close range!
67th min: Brighton & Hove Albion 1-1 Southampton (Disallowed Cameron Archer goal)
Ryan Fraser finds himself with space on the left flank and crosses across the penalty area towards an onside Cameron Archer, but VAR rules the goal out after suggesting that Adam Armstrong interfering with play from an offside position!
A controversial moment!
MAN OF THE MATCH - TYLER DIBLING
Tyler Dibling might not have grabbed a goal or an assist, but his impact on the match was once again exceptional.
The forward played six passes into the final third, managed to create two chances and completed four dribbles, the most of anybody on the pitch.
Perhaps most impressive was the winger's attitude without the ball considering he contested a staggering 27 duels, nine more than Georginio Rutter, who contested the second most of any player on Friday night.
BRIGHTON & HOVE ALBION VS. SOUTHAMPTON MATCH STATS
Possession: Brighton & Hove Albion 53%-47% Southampton
Shots: Brighton & Hove Albion 22-10 Southampton
Shots on target: Brighton & Hove Albion 5-2 Southampton
Corners: Brighton & Hove Albion 7-6 Southampton
Fouls: Brighton & Hove Albion 20-16 Southampton
BEST STAT
WHAT NEXT?
Brighton will take on Fulham on December 5 in their next outing in the Premier League before a clash against Leicester City on December 12.
Meanwhile, Southampton have a difficult set of league fixtures on the horizon, with a game at Stamford Bridge against Chelsea on December 4 followed by matches against Aston Villa and Tottenham Hotspur.