The French Prince did some growing up Sunday night.

In a closely contested game at a raucous Madison Square Garden, 19-year-old rookie Frank Ntilikina found himself on the floor during crunch time.

And the eighth-overall pick in this year’s draft delivered. Ntilikina, who set season-high with 10 points and added seven assists in 24 minutes, contributed on both ends of the floor as the Knicks came from behind to beat the Pacers, 108-101.

Ntilikina also notched two steals and hit two big 3-pointers in the fourth quarter, including one that put the Knicks up for good at 102-99 with 1:34 remaining.

Coach Jeff Hornacek trusted the youngster down the stretch, mainly because of his defensive prowess. The 6-foot-5 Ntilikina managed to disrupt the Pacers’ offensive flow by pressuring the ball full-court.

“Defensively, it’s incredible [what he can do],” Tim Hardaway Jr. said. “He picks a guy up full-court. He’s so long and athletic. And he’s got great hands. He just irritates that ball handler.”

Yet for the first time all season, Ntilikina looked as comfortable on the other end of the floor, facilitating out of the pick-and-roll and shooting with confidence.

“He shot it with [the mentality] ‘OK, I’m going to make this one,’” Hornacek said of Ntilikina’s late 3-pointer. “There was no doubt. That’s great to see in a 19-year-old.