GLENDALE, Ariz. -- Gonzaga will play for its first national title, but the Bulldogs took the hard way to Monday's final.
The Bulldogs squandered all of a 14-point second-half lead before rallying and holding on with two late free throws, ending the surprising tournament run of South Carolina with a 77-73 victory in a Final Four game at University of Phoenix Stadium on Saturday.
Point guard Nigel Williams-Goss led the way with 23 points, five rebounds and six assists, and 7-foot freshman Zach Collins came off the bench to post 14 points, a career-high 13 rebounds and six blocked shots.
Backup post player Killian Tillie made two free throws with 2.2 seconds left to seal the victory.
Gonzaga (37-1) will play the winner of North Carolina-Oregon on Monday night.
Top-seeded Gonzaga was on cruise control with about 11 minutes left, up 65-51 when Williams-Goss flipped in a driving layup and made a free throw for a three-point play.
South Carolina forward Chris Silva answered with a three-point play of his own, igniting a 16-0 run in the next 3:33, capped by two free throws by Rakym Felder for a 67-65 lead with 7:06 to go.
Collins regained the lead for Gonzaga when his 3-pointer bounced around and in, starting a 7-0 run in which center Przemek Karnowski had a dunk and a layup.
South Carolina had a chance to tie the score at 74, but Felder's spinning layup was blocked by Collins, who was fouled with 1:35 to go. He made one attempt.
The Gamecocks missed two shots on the other end but got one more chance to tie the score, taking possession with 12.7 seconds left. They didn't get a shot.
Gonzaga guard Josh Perkins committed a foul with 3.5 seconds to go, sending guard Sindarius Thornwell to the line. He made the first and line-drived the second for a deliberate miss, but the rebound stayed near the rim, allowing Tillie to grab it and be fouled.
Tillie made both ends of a one-and-one with 2.2 seconds left.
The Gamecocks (26-11) had reached their first Final Four as a No. 7 seed on the strength of Thornwell's scoring and havoc-creating defense.
But Gonzaga shot 48.3 percent from the field and Thornwell, who averaged a tournament-best 25.8 points before Saturday, might still have been feeling the effects of an illness that kept him out of practice Thursday. He finished with 15 points on 4-of-12 shooting.
Thornwell didn't score until the 6:25 mark of the first half.
Guard PJ Dozier had 17 points to lead South Carolina, which had been strong in the second half throughout the NCAA Tournament, outscoring its opponents by an average of 13.5 points after halftime. This comeback came up just short.
NOTES: Gonzaga C Przemek Karnowski sat out the final 5:12 of the first half after getting poked in the right eye. He received treatment at halftime and started the second half. ... South Carolina F Chris Silva had 13 points and 13 rebounds. ... Gonzaga is 26-17 in the NCAA Tournament under coach Mark Few, who has led the program to the NCAAs in each of his 18 seasons. ... South Carolina G Sindarius Thornwell, going 5 of 6 from the free throw line, moved into third place on the program's career list for made free throws. ... John Higgins, who received death threats from Kentucky fans after working the Wildcats' loss in the Elite Eight last week, was one of three officials for the game. ... Legendary Gonzaga PG John Stockton attended the game.