Saints will host Arsenal in the FA Youth Cup next month after beating Norwich City at St Mary's last night.
Right back Craig Richards scored the goal that gave Saints' youngsters a 19th win in 20 league and cup games and a place against Arsenal, the only team to beat them this season, in the fifth round.
Richards stabbed home the 16th-minute winner from six yards after Norwich goalkeeper Joe Lewis failed to hold on to an inswinging free kick from midfielder Tim Sparv.
Now they are set to play Arsenal before February 22 - and may play the north London giants in a fortnight's time.
Gunners academy director Liam Brady was in the St Mary's stands last night along with former Saints boss Steve Wigley, who was back at the club for the first time since being replaced by Harry Redknapp last month.
Redknapp watched the Saints youngsters for the first time alongside Jim Smith and Kevin Bond in the directors' box - after popping into the home dressing room to wish them luck before kick-off.
But Norwich proved dogged opposition.
The visitors only forced Saints goalkeeper Andrew McNeil into two saves, an acrobatic tip over the cross bar in the fifth minute and a fumbled 39th-minute stop from 20 yards after Lee Howlett had been allowed to run unchallenged.
But Norwich proved hard to break down and in the 77th minute they came close to forcing extra time when Robert Eagle shuddered McLeil's left post with a powerful 25-yard cross shot.
Saints were restricted to chances from long range, with defender Sean Rudd, striker David McGoldrick and Sparv all firing from 20 yards in the last five minutes of the first half.
Finnish midfielder Sparv also had a shot from the corner of the Norwich penalty cleared off the line after left-winger Nathan Dyer had dispossessed Lewis in the 64th minute.
But that was as close as Saints came to doubling their advantage.
Left back Kyle Critchell's persistence nearly paid off midway through the second half, but after charging through a succession of Norwich challenges, he could only find the side netting.
With the last kick of the match, and with Norwich keeper Lewis up for a corner, the pacy Dyer had a chance to secure Saints' passage into round five - but missed the open goal from inside his own half.
Wideman Dyer was Saints' biggest attacking threat, while captain Martin Cranie was outstanding at the heart of the defence.
But Saints coach Georges Prost wished his players had made more use of wingers Dyer and Theo Walcott.
He said: "It was a typical cup game, there was a lot of enthusiasm and commitment and we didn't play our usual football.
"The lads were a bit tense but we didn't use our wide players enough. Other teams are in trouble when we use Theo and Nathan but Norwich made it very difficult. They're a strong team and were dangerous at set plays so we're happy with the win.
"But we hope to play better against Arsenal. It will be very very difficult. They're a good team but we will be at home again."
Saints will be hoping for a bigger crowd for the visit of Arsenal than the 842 that watched last night's action.
Saints: McNeil, Richards, Cranie (capt), Rudd, Critchell, Walcott, Sparv, James, Dyer, McGoldrick, Best. Subs not used: Wallis-Tayler, Harrison, Condesso, Lallana, Mulvany.
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