Both sides were playing in their second U18 Premier League Cup fixture of the group stage, with Leicester defeating Newcastle United 3-0 seven days ago and the Saints losing out to Nottingham Forest last time out.
However, it would be the hosts who got off the mark in this season’s competition, moving level with the Foxes on three points in Group A, thanks to two goals during the opening 45 minutes in Totton.
Midfielder Fedel Ross-Lang converted a 20th-minute penalty to get Southampton up and running before Kamari Doyle assisted Dominic Ballard, who found the net on the stroke of half-time.
That’s how things stayed throughout the second half, despite City’s best efforts to get back into the game, and they must now regroup ahead of returning to Premier League U18 South duties on Saturday 23 October.
The young Foxes are set to face Arsenal Under-18s at LCFC Training Ground in Seagrave (11:30am BST kick-off).
City: Doherty; Grist (Read 65’), Godsmark-Ford, Wilson-Brown; Kutshienza, Cartwright, Cover (Lewis 72’), Lindsay; Alves (Javid 58’), Popov, Pennant.
Unused subs: Addai, Dawkins.