Charlie Austin’s late header helped Southampton march past Brighton 1-0 and into the Carabao Cup third round.
Austin needed just seven minutes from his introduction to make the ultimate impact, as he connected with Nathan Redmond for the match winner and a first Saints victory on the season.
A much changed Southampton, which finished as runners-up in the competition in 2017, pounced early but had to fend off a youthful Brighton side that included under-23 players Ben Barclay, Will Collar and Viktor Gyokeres.
Southampton nearly nudge ahead with eight minutes gone when Mohamed Elyounoussi saw his initial attempt from point-blank saved by David Button, before Maya Yoshida’s follow-up was cleared to safety.
Gyokeres was lively and forced Southampton debutant Angus Gunn into a pair of saves after the break, with the keeper making a professional stop against a header sent across goal.
But a double substitution — Redmond and Austin — with nine minutes remaining, however, proved the difference in a tight contest.
Austin had an effort cleared off the line by Bernardo shortly after he came on, but ruffled the back of the net moments later to ensure Southampton’s passage to the next round.
Brighton: Button, Suttner, Bernardo, Collar, Barclay, Bissouma, Kayal (Connolly 90), Gyokeres, Gross (Propper 63), Jahanbakhsh, Locadia.
Unused subs: Knockart (GK), Montoya, Stephens, Balogun, Steele.
Bookings: Bissouma (32).
Southampton: Gunn, Targett, Yoshida, Stephens, Bednarek, Ward-Prowse, Romeu (Gallagher 70), Armstrong (Redmond 81), Davis, Elyounoussi, Gabbiadini (Austin 81).
Unused subs: Lewis (GK), Hoedt, Vestergaard, McQueen.
Goals: Austin (88).
Bookings: Davis (41), Bednarek (82).