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.

“He’s finding his way out there. It says a lot about him and how he plays with confidence. He’s not afraid of the moment.”

When asked what went through his head after he nailed the clutch 3 that sent the crowd into a frenzy, Ntilikina said he was just trying to stay focused on finishing the game.

The Frenchman had shown flashes through his first eight games, but nothing as promising as what he displayed Sunday.

“I had that confidence,” Ntilikina said. “But being comfortable on the court took time. I think tonight was a good step and what I look to do in the future.”

Shooting guard Courtney Lee saw a clear transformation in his teammate.

“Sometimes he gets nervous out there, overthinking,” he said. “But tonight he was just playing.

“He on that building for a reason,” Lee said, referring to a massive picture of Ntilikina plastered on a skyscraper outside the Garden.

The future looks a little brighter following the victory, but Ntilikina isn’t thinking too far ahead.

“We don’t want to be good in the future,” he said. “We want to be good right now. We want to grow up right now.”