LAS VEGAS -- In the second half of his team's electric 84-81 win over No. 1 Gonzaga on Friday night in front of a sold-out T-Mobile Arena crowd, Duke forward Paolo Banchero experienced a terrible case of deja vu.

His cramping issues -- the same cramping issues that had interrupted his debut in a season-opening win over Kentucky -- had returned and stalled him after he scored 20 of his game-high 21 points in the first half.

"I'm not sure what it is, this game, the Kentucky game," said Banchero, ESPN's projected No. 2 pick in the 2022 NBA draft. "I haven't cramped all season except those two games. Once I felt it, I tried to run it off. ... I almost fell over. Both my quads locked up. At that point, I had to come out."

Banchero had to leave the game to get an IV but would return with nearly eight minutes to play. He scored just one point in the second half.

With Banchero ailing, however, the No. 5 Blue Devils showcased their depth and turned to a cast of co-stars who helped them capture a signature win against the nation's top team.

Wendell Moore Jr., who said he could only relay the "PG version" of the pep talk he gave his teammates in the second half as Gonzaga continued to fight, made two free throws that gave Duke a four-point lead with 19 seconds to play and finished with 20 points in the game.

Mark Williams might have been the MVP on Friday night. His perfect defense on Drew Timme's shot in the paint with nearly 30 seconds to go was just one of the many clutch plays he made in a performance that included 17 points, nine rebounds and five blocks.

"I give credit to my teammates, especially today," Williams said after the game. "They found me in a lot of the right places."

But Gonzaga also managed to weather adversity to keep the game close. Despite Banchero's dominant effort in the first half, Gonzaga entered the break down by three. Chet Holmgren (16 points, seven rebounds and three blocks), whom ESPN projects as the No. 1 pick in the 2022 draft, committed his second foul with 10:23 remaining in the first half and didn't return before halftime. And Timme missed a critical six-minute stretch after picking up his fourth foul late in the second half.

But Julian Strawther, a Las Vegas native who had family members and friends in the crowd, stepped up and finished with 20 points and 10 rebounds before fouling out of the game.

There were eight lead changes in the second half, but neither team led by more than five.

In the end, however, Banchero's hot start and the determination and athleticism on Duke's roster gave the Blue Devils an edge. Duke scored 23 points off Gonzaga's 17 turnovers. Gonzaga committed turnovers on nearly one-fourth of its possessions against the Blue Devils. But the Bulldogs still had a chance to win late after "getting punched in the mouth" early, Gonzaga coach Mark Few said.

"It just came down to them making one more shot than we did down the stretch," Few said.

Everything about No. 1 Gonzaga's matchup against No. 5 Duke at T-Mobile Arena felt magnified.

The streets around the building had been blocked off by police cars and security was tight. In the moments before the game, some fans scrambled to find tickets. As tipoff approached, the most expensive courtside seats were going for nearly $8,000.

Brooks Koepka and Floyd Mayweather Jr. -- wearing a chain that glistened across the building -- were part of the crowd of 20,389 that filled the arena and set a record for the largest basketball crowd in Nevada history.

"This was a really big time game," coach Mike Krzyzewski said. "What a great crowd."

Said Timme: "It felt like a Final-Four type game. The atmosphere was great. It was two Goliaths going at it."