NBA

Smith comes out firing in Knicks debut

He came mostly because of Carmelo Anthony, partly because of Mike D’Antoni’s offense and partly to be back in the region where he was raised.

Back from a stint playing in China, J.R. Smith, the former Nuggets shooting guard out of Freehold, N.J., made his Knicks debut in yesterday’s giant 104-97 victory over the Mavericks without so much as a single practice. He made a big impact in 29:43 of playing, scoring 15 points after hitting three of his first four shots, all 3-pointers, and invigorating the club early as it built a 32-20 lead after one quarter.

Smith got a little too shot-happy after his first-quarter burst and finished 6-of-16 (3-of-9 on 3-pointers), but proved he can add to the Knicks’ firepower.

After two long conversations with Anthony, his former Nuggets teammate, Smith decided to sign with the Knicks over the Clippers and Lakers.

“Melo sealed the deal for me,’’ Smith said. “Chris Paul [of the Clippers] and Melo are the godfathers of my two daughters. After playing with him in Denver and telling me what type of atmosphere this really was, he sealed the deal 100 percent.

“I really looked at the situation at hand, playing in L.A., playing at home,’’ Smith added. “It was really a no-brainer, playing with the system here that fits in right. It’s a perfect situation for me.’’

When Smith checked into the game with 5:43 left in the first quarter for Amar’e Stoudemire, the first guy off the bench, he received a warm welcome from the Garden crowd. Smith wore No. 8, his number as a high-school football player in New Jersey and the number of popular ex-Knicks Danilo Gallinari and Latrell Sprewell.

Smith wore No. 1, Stoudemire’s jersey number, with the Nuggets, and in China had No. 23, which is Toney Douglas’ number.

On his first possession, Smith, with a reputation as a gunner, passed twice, got the ball back and sank a stepback 3-pointer for a 21-18 lead.

On the next possession, Smith passed again, and after swift ball movement around the horn, took a pass from the left wing and sank a wide-open trey.

“The first five minutes was really mind-blowing,” Smith said. “The whole time during warmups, I’m sitting there thinking, ‘This is crazy. I’m at the Garden. I’m wearing a Knick uniform. This is crazy. I never would’ve imagined this in a million years.’ And to be out there for that first five minutes, the first thing I was thinking was, ‘Don’t airball your first shot.’ You never want to live that down in New York City, so once I made the first one it really got me going.”

Smith, who has a history of off-court problems, says he is a perfect fit for D’Antoni’s speedball offense.

“His offense and coaching matches my game to the T,’’ Smith said. “Fast-paced, run the lane, if you’re open, shoot the ball. And now he’s more into defense. The pieces they’ve put around the team, the guys are really, really defensive oriented.’’

Despite Smith tweeting he would debut yesterday, D’Antoni thought it wasn’t possible without a practice. However, D’Antoni gave it more thought after speaking to Smith two hours before tip-off.

“Coach really shocked me,’’ Smith said. “He said I wasn’t going to play or I was going to play limited minutes. My teammates were unbelievable in helping me.’’