With Arsenal having already clinched a berth in Saturday's final at the Pizza Hut Park complex in Frisco, Texas, the Fire edged Arsenal, 1-0, on the final day of group play to reach the final, where it again prevailed, 1-0.
Conor O'Brien fed a cutting Matthew Picolli, who slipped through three defenders and scored for the only goal of the game.
Goalie Tommy Booth made several late saves to preserve the upset for the Long Island club.
The Dallas Texans Red and Real SoCal joined Arsenal as the only boys teams to ever capture three straight national titles.
U.S. U-20 international Andre Akpan scored the only goal as the Texans again beat the Chicago Magic in a national final -- this time, 1-0, for the McGuire Cup title. The Dallas club thus completed its run at the youth level as one of the most decorated club in history. It is the only American team to ever win the Dallas Cup's Super Group.
Zach Zerrenner scored in the 4th minute for Real So Cal, which gained revenge for its loss to the Michigan Wolves in group play with a 1-0 win in the U-16 boys final.
Jonathan Guzman, one of the most exciting players at the National Championships, set up both goals for the Baltimore Casa Mia Bays in their 2-1 overtime win over West Coast FC in the U-14 boys final.
Dallas club Andromeda won the U-17 boys championship with a victory over FC Milwaukee on penalty kicks after the Wisconsin club twice came back from one-goal deficits to earn a 2-2 tie.