Quincy Douby missed his first three shots yesterday, but then, as Grady coach Jack Ringel said, the senior “went absolutely berserk.”

The 6-foot-4, Hofstra-bound Douby wound up hitting 18 of 21 three-pointers and scored 63 points as the Falcons beat host FDR 112-59. Ringel took Douby out just over a minute into the fourth quarter, as Grady improved to 7-2, 6-1 in PSAL Brooklyn A.

“It was hard to come out, but I understood,” said Douby, who had set a career-high with 39 against Jefferson in his previous game. “I was on fire and just wanted to keep shooting. I wanted to score 50 points in a game this year, but I never thought I would do this.”

Neither did Ringel.

“Everybody was in awe,” said Ringel, whose team faces Amityville and its talented center Jason Fraser on Saturday. “I’ve been coaching basketball a long time and I’ve never seen anything close to that.”