Taking the lead in Seagrave, when Lorenz Hutchinson set up Riley Carr to find the net after half an hour, the opener was soon cancelled out by Brodie Dair's equaliser for the Cottagers.
Fulham substitute Markuss Gomins then made an immediate impact from the bench, scoring six minutes after coming onto the pitch to ensure it was the away side who claimed an opening day victory at LCFC Training Ground.
The Foxes youngsters will have another chance to put points on the board in U18 Premier League South on Saturday (12pm BST kick-off), facing Reading at Bearwood Park Training Ground - the first away game of 25/26 for the side coached by Adam Barradell.
The details...
City: Marson, Aideed, Toko, Diallo, Daniels; Carr, Lawrence, March, Owusu (Fletcher, 76'); Hutchinson, Motsi (Corden, 60').
Unused subs: Dignum, Stretton, Manyumba.
Goal: Carr 31'.