The teenager kept his nerve to win the final at Springfield on Thursday night on a sudden-death shoot-out against club colleague Brandon McGlurg.
Both players had scored a maximum five kicks in the final to eliminate St John’s Michael Freitas and Rozel Rovers’ Matthew Wellman who scored four and three respectively.
Tostevin took the prize of a trip to watch Arsenal’s forthcoming home Premier League match against Reading, from a hospitality suite at the Emirates Stadium, when goalkeeper Daniel Kitchen saved McGlurg’s first sudden-death kick.