GLENDALE, Ariz. — College roommates often tell each other just about every thought, no matter how outlandish, assuming it will stay among friends. That confidence code apparently doesn’t apply to Gonzaga’s Nigel Williams-Goss, who freely disclosed what Zach Collins had expressed Saturday before the biggest game of their careers.

“He said, ‘Look, I wouldn’t want to be playing against me today,’” Williams-Goss said. “I looked at him and I said, ‘All right, let’s do it then.’”

They did it as one, Williams-Goss controlling the game with his shotmaking and Collins contributing across the board to help their tiny school come up big in a battle of Final Four newcomers.

The Bulldogs survived a second half of epic momentum swings, holding on for a 77-73 victory over South Carolina in an NCAA tournament semifinal at University of Phoenix Stadium. The Bulldogs will play North Carolina for the national championship on Monday.

Gonzaga (37-1) persevered with some pluck and some luck, Collins’ three-pointer nudging them ahead to stay with 6:42 left after bouncing off the back of the rim and rolling into the basket.

Williams-Goss led all scorers with 23 points on nine-for-16 shooting and Collins was everywhere the Bulldogs needed him to be, finishing with 14 points, 13 rebounds and six momentum-shifting blocks.

“I knew I had a couple of rough games before this,” said Collins, a freshman forward. “And I wanted to come out and just play a lot better for my team. In my head, I just said I had no choice. And that’s when I told Nigel I just felt really good.”

Collins also was head cheerleader after Gonzaga reserve forward Killian Tillie made the first of two free throws with 2.2 seconds remaining, chest-bumping his teammate before Tillie’s second free throw dropped through the net to give his team a four-point lead. The Bulldogs surged onto the court in celebration after a halfcourt heave at the buzzer by South Carolina’s PJ Dozier was well off the mark.

It was a victory that was a tribute to Dan Dickau, Adam Morrison and all the other former Bulldogs greats, the school’s 19th consecutive appearance in the NCAA tournament resulting in the Bulldogs’ first chance to win a title. Just don’t call them the darling underdogs.

“It’s not 1997 anymore,” South Carolina Coach Frank Martin said dryly. “They were Cinderella and all that pretty stuff in ‘97. They’ve been in this thing for 20 consecutive years. They’re as high major as high major can get.”

Gonzaga showed some smarts in the final seconds, intentionally fouling South Carolina’s Sindarius Thornwell with 3.5 seconds left with the Gamecocks needing a three-pointer to tie the score.

“I thought we waited a little long to do that, quite honestly,” Bulldogs Coach Mark Few said. “But (Josh Perkins) went out and grabbed him before he was in the shooting motion and as it turned out you couldn’t be any better, you know?”

Thornwell made the first free throw but purposely bounced the second off the back of the rim, allowing Tillie to grab the rebound and make the free throws that put the game out of reach.

The wild ending came after Gonzaga had built a 14-point lead and withstood a 16-0 surge by South Carolina before generating a 7-0 run of its own. Collins’ lob over the top of the Gamecocks defense led to a layup by teammate Przemek Karnowski that gave Gonzaga a 72-67 lead.

Karnowski, who had returned after taking an inadvertent hand to the eye in the first half that resulted in blurry vision, flapped his arms in celebration as he walked toward the bench during the timeout that followed.

The Gamecocks (26-11) closed to within 75-72 thanks in part to a spinning layup by Thornwell and a Dozier putback, getting possession with 12.7 seconds left after Gonzaga’s Johnathan Williams lost the ball out of bounds chasing a rebound. But Perkins’ foul several seconds later thwarted the Gamecocks’ plans to get off a tying shot.

Few, who had long been criticized for building a program that was good but not just good enough to beat its heavyweight counterparts, attempted a handstand in the locker room after the game.

“We’ve been on this team to show some emotion, because there’s always expectations with Gonzaga teams that they should win every game,” Few said. “Sometimes I worry that my guys get, like, it’s a job. And we’ve been on them to show emotion. So they’re always on me to show emotion after a win. So that’s my fairly weak effort of showing emotion.”