What’s with all of these NBA rookies trying to challenge veterans at the rim? On Sunday, it was Lonzo Ball attempting to take it to the rack against Anthony Davis late in the fourth quarter of the Lakers’ game against the Pelicans. AD welcomed Lonzo to the league by rejecting him and turning what could have been 2 points for the Lakers into a fast break the other way for the Pelicans. And on Monday night, Mavericks rookie Dennis Smith Jr.—who, like Lonzo, will likely be in the running for the Rookie of the Year award this season—tried something similar during his team’s game against the Warriors, with similar results.

With Dallas trailing Golden State by 11 points late in the third quarter, Smith Jr. got the ball and took it directly at Draymond Green in the paint. Even though Green has made a living preventing opposing players—including guys like LeBron James and Blake Griffin—from dunking on him, Smith Jr. decided that he was going to try and dunk over Green anyway. And while he almost did it, Green shut down the idea of Smith Jr. putting him on a poster with the quickness. He was whistled for a foul on the play, but he got just enough of the ball to stop Smith Jr. from successfully completing his dunk attempt.

Green talked some major trash after Smith Jr. tried to dunk on him, too. As you can clearly see in the clip above, he yelled, "You’ll never dunk on me," as Smith Jr. made his way to the free-throw line. Green also spoke with reporters after the game and reiterated what he said to Smith Jr.

"Yeah, that shit ain’t happening," Green said. "This ain’t Summer League, bro. Not just gonna dunk on nobody. Better luck next time. It ain’t happening. C’mon, dude."

Smith Jr. was also asked about the moment, and he responded to Green’s trash talk by saying, "I don’t know what he was talking about. You can’t say nothing if you foul me."

Additionally, Smith Jr. said that, if you couldn’t already tell, he’s not going to back down from Green or anyone else on the court now that he’s made it to the NBA.

"I’m not doing it just to let people know that I’m not backing down," he said. "I just don’t back down for nobody. That’s just how I am. All that extra stuff, I don’t really dabble in that. I do what I have to do. I handle my business. That’s about it."

Green’s mom Mary Babers-Green got in on the action as well. On Twitter, one NBA fan accused Green of fouling Smith Jr. "all the damn time" to prevent him from dunking on him.

And Babers-Green responded by blocking the fan at the rim, just like Green did to Smith Jr.

The Warriors went on to beat the Mavericks 133-103. Green finished the game with 10 points, 7 rebounds, and 8 assists, while Smith Jr. ended the night with 10 points 6 rebounds, and 1 assist.