In the fourth round of the Carabao Cup, Che Adams scored two goals as Saints came from behind to beat Lincoln City.
The win gives Nathan Jones his first win as Saints boss, after he lost his only previous match in charge atLiverpool.
His side fell behind when he didn't deal with the clearance.
Adams scored on either side of the break.
They have not scored more than one goal in a game since their victory over Chelsea.
They lost to Manchester United in the final of the competition last year.
After waiting more than six weeks for his home debut, Jones would have liked a better start, but the ball bounced in after a miscued clearance, as Paudie O'Connor tried to get the ball back.
It took a while for the Saints to get going but they found an equalising goal when Adams rose highest to head in a corner.
Lincoln, playing in the fourth round for the first time since 1967, were the better side at the start of the second half and Jones made a triple substitution.
It brought immediate improvement, and the second goal arrived when the acrobatic effort was blocked and then bundled over the line by Adams for his second double in the competition this season.
Samuel Edozie and Adams both missed gilt-edged chances to add to the scoring for Saints as Lincoln pushed for an equalising goal.