Black Cats book Blues date
A rare Phil Bardsley goal helped book Sunderland a Capital One Cup quarter-final clash with Chelsea next month as the defender continued his rehabilitation under Gus Poyet.
The 28-year-old set the Black Cats on the road to a 2-1 victory, just their fourth of the season and third in the same competition, after finding the net for the first time since a 1-1 draw with the Saints in May.
The former Manchester United full-back struck from close range 14 minutes into the second half after former Sunderland goalkeeper Kelvin Davis had parried Jozy Altidore's header.
Substitute Sebastian Larsson looked to have wrapped up the win with a second goal four minutes from time, but defender Maya Yoshida's late header set up a tense conclusion.
Bardsley almost left Sunderland in the summer after being discarded by former boss Paolo Di Canio when a photo emerged of him covered in £50 notes while lying on a casino floor, followed by an ill-judged Twitter message.
The Black Cats enjoyed the better of the early chances, although neither Davis nor opposite number Vito Mannone were unduly busy in front of a muted crowd of just 15,966 at the Stadium of Light.
The Saints keeper had to block Craig Gardner's 48th-minute snapshot with his legs, but was otherwise largely untroubled apart from the goals.
The Black Cats became the first team to defeat Southampton in nine attempts in all competitions since August. Saints boss Mauricio Pochettino replaced 10 of the men who started at Stoke at the weekend while Poyet retained only seven of his strongest side.