Knicks rookie Frank Ntilikina stood up to LeBron James, even — gasp! — shoved the King. He went up against fellow rookie Lonzo Ball, who has about three tons of hype on him. Ntilikina outscored Ball, 7-2, in the fourth quarter and overtime. Ntilikina improves by the hour. But perhaps the most impressive aspect of the eighth pick in June’s draft? “When people ask me about him, I [say], ‘You know he’s 19?’ and they go, ‘What?’ ” Knicks starting point guard and Ntilikina mentor Jarrett Jack, 34, said Wednesday after practice in Tarrytown. “He just turned 19 some months ago. He won’t turn 20 until next year. And they go, ‘Oh.’ They’re kind of taken back when I tell them that.” More and more, the 6-foot-5, 190-pound teen is gaining the experience required to run an NBA team. Ntilikina played the final 21 minutes Tuesday of the Knicks’ 113-109 overtime victory against the Lakers. Ntilikina, who arrived from France with a solid defensive reputation, is improving his offensive game. The shot and the overall offense need lots of work. But it’s coming. After all, Ntilikina has time. In case you haven’t heard, he’s 19.