Cooper Flagg made his NBA Summer League debut, and it came with a bit of a twist.

The future face of the association went toe-to-toe with the current face's son, Bronny James, and Flagg has the upper hand after their first bout.

The NBA's all-time points leader's son missed a potential game-winning three-pointer in the final seconds that gave Flagg and his Mavs an 87-85 victory.

Cooper Flagg, #32 of the Dallas Mavericks, is guarded by Bronny James, #9 of the Los Angeles Lakers, in the first half of a 2025 NBA Summer League game at the Thomas & Mack Center on July 10, 2025, in Las Vegas, Nevada.  (Ethan Miller/Getty Images)

Ryan Nembhard gave Dallas the lead with 1:03 to go on a three-pointer assisted by Flagg - seconds after Flagg swatted away a shot from L.A.'s DJ Steward. Los Angeles called a timeout, and they brought in James.

Los Angeles got fouled but missed both free-throws. Flagg then attempted to increase the lead with 15 seconds left but missed his shot.

James then tried for the game-winner, but missed, and the Mavs were able to come away with the victory.

Flagg struggled from the floor, scoring just 10 points on 5-for-21 shooting, with six of those points coming in a 90-second span in the first quarter. He grabbed six rebounds, handed out four assists, and had three steals and a block in 32 minutes played. His first bucket, though, was a thunderous slam on a coast-to-coast.

"I couldn’t really get into a rhythm, it’s a different environment, obviously very different from college, it’s probably very different from what the real NBA is gonna be like," Flagg said after the game. "The coaches had a lot of confidence in me. They’ve been telling me they want me to experiment, try some new things, and I was trying to be aggressive, and that’s new for me too.

"I would say that might be one of the worst games in my life, but we got the win, that’s what really matters to me."

Bronny James, #9 of the Los Angeles Lakers, and Cooper Flagg, #32 of the Dallas Mavericks, go after a loose ball in the first half of a 2025 NBA Summer League game at the Thomas & Mack Center on July 10, 2025, in Las Vegas, Nevada. (Ian Maule/Getty Images)

Flagg admitted he was "a little nervous."

"It’s a new environment, a lot of new fans and whatnot," Flagg said. "So I was a little nervous, a little excited, but just happy to be here. It’s a dream come true, so I’m just trying to enjoy the moment."

James buried his first attempt over Flagg, and then hit a 3-pointer after the 6-foot-8 Duke product missed his second attempt to give the Lakers a 5-0 lead.

The two had several tough plays against one another, and shared plenty of laughs on the court.

James scored eight points to go along with two boards and two assists.

Bronny James, #9 of the Los Angeles Lakers, is guarded by Cooper Flagg, #32 of the Dallas Mavericks, in the first half of a 2025 NBA Summer League game at the Thomas & Mack Center on July 10, 2025, in Las Vegas, Nevada. (Ethan Miller/Getty Images)

James was the 55th pick in last year's NBA Draft out of USC. Flagg went No. 1 overall late last month to the Dallas Mavericks.

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