If Southampton are to stay in the Premier League, they cannot afford to lose this kind of match. Nigel Adkins's side had the perfect opportunity to put breathing space between themselves and the bottom three for the first time this season following Wigan's defeat to Arsenal earlier in the day but they blew it, instead allowing Sunderland to snatch a crucial victory that moved the Black Cats four points clear of the relegation zone and should do wonders for their confidence ahead of a daunting run of fixtures.
Southampton, despite missing their injured captain Adam Lallana, swarmed all over the visitors in the early stages and will rue not putting the game to bed in that period. Minutes after a Stephane Sessegnon chance, Rickie Lambert broke down the left and found Jason Puncheon, who scuffed an inviting chance wide from the edge of the area when he should have at least tested Simon Mignolet.
It was all Southampton and a goal looked inevitable; and with a more clinical striker than Emmanuel Mayuka – the 22-year-old Zambian was making his first league start in Lallana's absence – it would no doubt have arrived. However, when he was played through, he shot tamely straight at Mignolet, who then reacted smartly to keep out Gaston Ramirez's swerving drive.
Just before half-time, the Saints were given a lesson in finishing by the ever-reliable Steven Fletcher. Although Sessegnon mishit a low cutback, the ball came to Fletcher, who swept it past Kelvin Davis from close range for his eighth goal since joining Sunderland from Wolves in the summer.
As much as Southampton attacked, there was not enough invention in the final third and although Sunderland survived a few hairy moments, the excellence of Carlos Cuellar and Ireland's John O'Shea ensured they held on for a victory that could ignite their stuttering season. It could spell doom for Southampton's.