The Saints' substitute ensured they left the Stadium of Light with a point and means Paolo Di Canio's side remain embroiled in a relegation battle in the lower half of the table
Paolo Di Canio likened Sunderland's comeback on Monday against Stoke to a night at the opera, as his side fought back to secure a point after being a goal and a man down following Gardner's dismissal, and there was similar drama here as each team scored late on.
Sunderland took the lead thanks to a thumping effort from Phil Bardsley, before one of Southampton's substitutes Jason Puncheon salvaged a point in the 76th minute.
The hosts came into the game in high spirits following their strong comeback to secure a point against Stoke. Craig Gardner was sent off in that game though, which meant Phil Bardsley started at right-back for Di Canio's men and Jack Colback moved into central midfield in Gardner's absence.
Southampton were still without the suspended Gaston Ramirez, though they did welcome back Morgan Schneiderlin, with Guly do Prado making way for a midfielder that has made more interceptions than any other in Europe's top four leagues.
The first real chance of note for either side came on the half-hour mark, when Simon Mignolet pulled off an impresive save from Jay Rodriguez.
Mignolet, making his 100th appearance for Sunderland, dived low to his right to keep out Rodriguez's sweeping effort after the former Burnley forward had hit the ball instinctively when it fell to him inside the crowded penalty area.
Adam Johnson passed up a glorious chance to put Sunderland ahead minutes before half-time when he shot tamely at Artur Boruc after being set up well by a cushioned header at a corner from John O'Shea.
More good goalkeeping from Mignolet kept Rodriguez at bay as Southampton started the second half strongly, before Danny Graham wasted a fine opportunity to end his 14-hour Premier League goal drought and put the hosts one up, when he struck air instead of the ball after great play from Danny Rose on the left.
Sunderland continued to stream forward in search of an opener, and in the 68th minute they got just that.
After Southampton failed to clear a cross from the left, Johnson showed the presence of mind to slip the ball to Bardsley in space on the right and he took a touch before unleasing a venomous strike that flicked off Jos Hooiveld and flew into the top left corner.
The hosts were not ahead for long though, as Southampton substitute Puncheon drew his side level just moments after coming on. Mignolet did brilliantly to keep out Rickie Lambert's inital header but he could do nothing about Puncheon's well-struck follow-up as it flew past him and into the net.
A wonderful stop from Mignolet in the 87th minute stopped Lambert from completing the comeback for Southampton, after the forward pulled away from John O'Shea and hit a low shot towards the bottom corner, as things ended all square.