LAS VEGAS — Cooper Flagg made his professional debut Thursday night in the NBA Summer League and celebrated an 87-85 win over Bronny James and the Los Angeles Lakers.

Flagg, of Newport, finished with 10 points on 5-for-21 shooting, including 0 for 5 from 3-point range. He also had six rebounds, four assists, three steals and one block. Though Flagg struggled at times to find his rhythm, there were flashes as to why he was chosen No. 1 overall in the NBA Draft last month, doing plenty of little things that helped the Mavericks seal the win, including a key block near the end of the game.

Flagg swatted DJ Steward’s attempt with 1:10 left in the game, and Ryan Nembhard made a 3-pointer at the other end to give Dallas the 87-85 lead.

Flagg strolled into UNLV’s Thomas and Mack Center at 4:17 p.m., wearing Dallas Mavericks gear, bright white New Balance shoes, and an emotionless look on his face as he passed through security.

Roughly 45 minutes later, he wore the same stone-cold face as he took the court for warmups shortly after 5 p.m.

His fans more than made up for it with plenty of energy, electrifying the jam-packed arena that cheered loudest when he was announced as a starter in his first Summer League game.

Flagg missed his first two shots, picked up his first foul just 46 seconds into the game, and gave the crowd what they’d been anticipating, going 1-on-1 with fellow fan favorite James.

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

Flagg excited the crowd at the 4:30 mark of the first quarter, jamming home his first points.

Early in the second quarter, Flagg nearly sent every fan in the building into a frenzy when he made a spin move into the paint and attempted a one-handed dunk over 7-foot Christian Koloko. The ball caromed off the back of the rim but still drew plenty of oohs and ahhs.

Generally filled with Lakers fans when the team plays in the summer, the arena was full of emotion with a fair share of Mavericks fans in attendance to see the 2025 national college player of the year.

Like 15-year-old Baer Epple of Seattle, who was seated with his father, Chad, in the third row from the court, donning a Dirk Nowitzki Mavericks jersey.

Epple said he’s a Mavericks fans and has been following Flagg since before his Duke days.

“Even more of a fan now that they got Cooper Flagg,” Epple said. “Hopefully he does good, that’d be pretty cool to see. I don’t want him to be like a bust or anything.”

Mavericks coach Jason Kidd told The Associated Press before the game he was looking for nothing more than effort and grit in his team’s opening game.

“This summer league is a little different when you have this type of turnout,” Kidd said. “But the guys have had a couple practices. There’s going to be some turnovers. I just want to see how they respond to a couple of mistakes being made; no one’s gonna play a perfect game and be unselfish.”

As for his prize draft pick: “We’re all excited,” Kidd said of Flagg. “Seen enough of him on tape, so now it’s good to see him on the floor.”