Brooklyn cops busted Keenen Upson, 20, as the gunman who opened fire on a crowd of spectators, wounding five, as they left a basketball game last week.

Upson was charged with assault, criminal possession of a weapon and reckless endangerment in the Jan. 14 shooting outside Bishop Loughlin HS in Fort Greene.

He allegedly started spraying lead at 10 p.m. in the schoolyard at Vanderbilt and Greene avenues. The victims, all 17 to 19 years old, were hit in the arms and legs, but there were no life-threatening injuries.

Another man, 18, was punched in the mouth during the ensuing melee.