Mauricio Pochettino's men only took four minutes to take advantage of the ample time and space afforded them as Jay Rodriguez took the ball on his chest on the edge before volleying into the far corner.
Southampton continued in the ascendancy and could have been further ahead by the time they added a second on 31 minutes – with the best chance falling to Rickie Lambert but he could only pull his volley wide from inside the box with 21 minutes gone.
It looked like it could be turning into a long afternoon for Gus Poyet when Dejan Lovren evaded the attentions of Wes Brown to angle a volley into the far corner but Sunderland had halved the deficit inside a minute.
Fabio Borini timed his run perfectly to meet an Adam Johnson cross, take it on the chest and scuff past Artur Boruc, and, despite a dramatic improvement in performance from the home side, that is how the half finished.
Sunderland carried some momentum into the second half and began to see more of the ball without hugely troubling the Southampton defence, bar a disallowed Borini strike for offside.
Poyet turned to his bench to try to salvage something from the game, and the introduction of Craig Gardner and Jack Colback brought some much needed creativity and they were level with 71 gone when Adam Johnson hammered home after a quick break.
Another substitute, Steven Fletcher had the best chance as the game drew to a close but his effort was smothered by Boruc.
Having lost a two-goal lead, the Saints also lost Gaston Ramírez and Lovren to serious-looking injuries.
4’ - Rodriguez goal - What a strike. A clearance finds its way to Rodriguez, who takes a touch on his chest before angling a volley into the far corner from the edge of the box. Mannone with no chance
31’ – Lovren strike - What a strike from the defender. The Saints win a corner, which is whipped in at pace and Lovren pulls off Wes Brown before he executes a wonderful flying volley into the far corner.
32’ - Borini halves the deficit - Sunderland cut the arrears. Johnson sends over a cross and Borini breaks the offside trap, takes it on his chest and fires past Boruc. Game on.
58- Fonte effort - Lallana wins a free-kick down the right. Davis whips it in and Fonte rises unopposed to head on goal but Mannone saves.
65 – Disallowed goal - Unlucky Borini, who thinks that he had broken the offside trap but he went a fraction too soon. Great finish, all the same.
71’ - Johnson strike - A lovely take by Ki on the run sees him take two players out of the game. He charges forward and finds Gardner who in turn feeds Johnson on the run and he lashes an effort past Boruc.
76’ – Fletcher chance - Sunderland load the box for the corner and an almighty scramble culminates in Boruc denying Fletcher at the near post.
Adam Johnson has scored in successive PL starts for the first time since October 2011 – when he scored in Man City’s 4-0 win at Blackburn and 4-1 home victory against Aston Villa.
Sunderland last came back to avoid defeat in a PL home match from a two-goal losing position with their 2-2 draw against Fulham in March 2013.
Southampton have never lost a PL match with a Saturday, 12.45pm [GMT] kick-off (three wins, three draws).
Sunderland have recorded their second comeback to win or draw a PL match having been two-goals down this season – they have done this more times than any other side this term (Aston Villa, Man Utd & Swansea have all done it once this season).
Can Sunderland turn around their home form? They have garnered a measly eight points at home this season. If they can improve that tally then they will surely stay up.
MAN OF THE MATCH
Fabio Borini (Sunderland): Was rewarded for effortless running with a fine goal and was unlucky not to get a second but went a fraction too soon.
Sunderland: Mannone 5, Bardsley 6, O'Shea 5, Brown 5, Alonso 5, Larsson 5, Cattermole 5, Ki 6, Johnson 6, Altidore 5, Borini 7. Subs: Gardner, Fletcher, Colback.
Southampton: Boruc 6, Chambers 6, Fonte 6, Lovren 6, Shaw 6, Schneiderlin 5, Cork 5, Rodriguez 6, Steven Davis 6, Lallana 6, Lambert 6. Subs: Yoshida 5, Ramirez 5, Ward-Prowse 5.