Jake Robinson became Brighton's youngest ever goalscorer as the Nationwide Division Two leaders eased into the second round of the LDV Vans Trophy.
Robinson, still only 16, created club history in the 88th minute when he slotted home a pass from Nathan Jones.
It rounded off a comfortable victory for the Seagulls against Nationwide Conference side Forest Green.
Robinson was introduced for his home debut early in the second half in place of the prolific Leon Knight.
Knight scored his 11th goal of the season from close range to give Brighton the lead in the 36th minute after tenacious work by his strike partner, Chris McPhee.
Brighton fielded close to a full-strength side for caretaker manager Bob Booker's second match in charge.
They were always in command, although Michels Kuipers had to make fine second-half saves from a Denny Ingram free kick and a Martin Foster shot to keep them ahead.
Brighton have now won their last five matches at the Withdean Stadium without conceding a goal.