A Duke commit, Flagg and his twin brother, Ace, returned to the arena where they won the Maine Class A state championship two seasons ago. They now play for Montverde (Fla.), the No. 1 team in the country, but their presence at the “Maine Event” was certain to draw interest — and a sold-out crowd of 6,122.

Flagg lived up to his billing. The 6-foot-9 forward had 23 points, 10 rebounds, five assists and eight blocks in a 95-51 blowout. Gonzaga, hoping to play the villain, fell behind by double digits before scoring a point but still came away with something from the experience.

“This is why you come to a school like ours and theirs,” Gonzaga Coach Steve Turner said, “to be in this type of environment you’ll see at the next level.”

Hundreds of fans arrived more than three hours before the game, rushing to their seats when the gates opened for the night’s first game, which pitted the Flagg’s old school, Nokomis, against a local rival. Then, during the featured matchup, they erupted in applause on every Flagg touch, “oohed” and “aahed” on each dunk. They booed when officials whistled Flagg for a double-dribble and jeered even louder when he got called for a foul while attempting to block a shot.

“We don’t see home pretty much at all anymore,” Flagg said. “It means everything to come back, see everybody and really feel the support in real time.”

When he checked into the game late in the second quarter after a rest on the bench, a young fan yelled, “I love you, Cooper!”

Reese McAvoy, 9, of Millinocket, wore a Team USA T-shirt with Flagg’s No. 9 that his mother made. McAvoy watches many Montverde games online and was wide-eyed seeing his hero’s highflying dunks in warmups.

“It’s awesome because I’ve seen Cooper on video and he’s inspiring me,” McAvoy said. “Not a lot of people from Maine go on to play pro sports, so that means he’s really special.”

Flagg grew up in Newport, a small town about two hours north of Portland. He attended Nokomis as freshman, winning the state championship with Ace and their older brother, Hunter, then a senior. Cooper and Ace transferred to Montverde shortly after.

Following his first season at the prep school, which is in a suburb of Orlando, Flagg reclassified from the Class of 2025 to 2024, jumping from a rising junior to a senior. Weeks later, he committed to the program he once described as his “dream school,” choosing the Blue Devils over reigning national champion U-Conn. in what many analysts deemed Duke’s opportunity to lose. Ace Flagg, a 6-7 forward with a handful of Division I offers, remains in the Class of 2025 and is a junior.

Cooper Flagg rose to national stardom during the summer of 2022 as a key contributor to Team USA’s gold medal at the FIBA Under-17 World Cup. Last summer, he and Ace willed their Maine United AAU basketball team to the finals of the Nike Peach Jam, the top grassroots tournament in the country. At that tournament, video surfaced of LeBron James watching Flagg play and later speaking with him; naturally, it went viral in the corners of social media obsessed with hoops.

Still, Flagg never lost his connection to home.

“Both boys have a ton of pride in that they’re representing the state of Maine and constantly go back to their Maine roots,” said Matt MacKenzie, who has trained the twins for years.

Turner, an assistant coach with FIBA squad, said he viewed the opportunity for Gonzaga to play in Maine as “nothing to lose” against a “high school all-star team” that features five of the top 48 ranked seniors in the country.

Gonzaga, which moved to No. 1 in The Washington Post’s rankings this week but has since dropped consecutive games — including a 65-57 result at Bishop O’Connell on Tuesday — will return home to a rugged Washington Catholic Athletic Conference schedule. The Eagles have three top-100 players of their own in the 2025 Class, as ranked by 247Sports: point guard Nyk Lewis (No. 53), combo guard Derek Dixon (No. 74) and center Christian Gurdak (91). But they were no match for Montverde in terms of star power.

Off the opening tip, Flagg leaked out and threw down a dunk. Heavy cheers followed and filled the gym throughout the night.

“It was just crazy,” Lewis said of the atmosphere.