Tim Hardaway Jr. didn’t need to win the game with 8.2 seconds left with a 17-foot left-baseline jumper to give the Knicks a 103-102 preseason win over the Celtics last night.

Hardaway had already proved plenty in the first 3 ½ quarters that he wasn’t like most rookies that ice runs through his veins part of the gene pool. Hardaway drained five of his first six shots including three straight 3-pointers.

But with his famous father Tim Hardaway Sr. on hand scouting for the Heat the game-winner was the cherry on top of the sundae.

Hardaway’s Knicks debut turned into a storybook tale as he floated in the jumper to repel the Celtics who had rallied from a 23-point fourth quarter deficit against the very end of the Knicks roster. Hardaway Sr. could be seen looking up to the ceiling howling after his son’s shot fell through.

“It was great’’ Hardaway Jr. said. “Everything you ask for and dreamed of came to reality. [My father] was out there scouting for the Heat and the same time supporting me. It was great to have a family figure out there.’’

Hardaway Sr. wasn’t allowed by Miami brass to be interviewed by MSG Network but a source said assistant general manager Allan Houston told him before the game his son was having a terrific training camp. There’s a logjam at shooting guard but the 24th pick of the draft is going to make it tough for coach Mike Woodson.

“That’s something to build on wow’’ said Metta World Peace who had a sweet-shooting Knicks debut himself with 13 points on 5-of-9 shooting. “Some you can’t see in the stats what a guy has in his heart. His first game and he wanted it bad and I’m pretty sure you are going to see a lot of big shots like that from him.’’

Hardaway’s jumper was smooth and clean. Missing most of summer league with a sprained wrist has not hurt him.

“I feel real good’’ he said. “Take them while you’re open don’t force too many. You don‘t get too many opportunities at this level you have to make the most of it.”