LOUISVILLE, Ky. >> Darrion Trammell converted a go-ahead free throw after he was fouled on a floater with 1.2 seconds left, and San Diego State powered its way into its first Final Four, grinding out a 57-56 victory over Creighton on Sunday in the NCAA tournament’s South Region final.

Lamont Butler scored 18 points and Trammell had 12 for the fifth-seeded Aztecs (31-6), who slowed down the high-scoring, sixth-seeded Bluejays (24-13) and became the first Mountain West Conference team to reach the national semifinals.

The experienced Aztecs, in their sixth season under coach Brian Dutcher, will play the surprising East Region champion, ninth-seeded Florida Atlantic, on Saturday in Houston for a spot in the national title game.

With the game at 56-all on San Diego State’s final possession, Trammell drove toward the free-throw line, elevated for the shot and was fouled by Creighton’s Ryan Nembhard. Trammell missed the first free throw but converted the second.

“I’ve been dreaming this my whole life, grateful to be here and thankful to everyone who believed in me,” Trammell said.

Creighton’s Baylor Scheierman threw the ensuing inbound pass the length of the floor. San Diego State’s Aguek Arop and Creighton’s Arthur Kaluma both jumped for it and the ball deflected out of bounds. Officials reviewed the play and determined that time had expired, and the celebration was on for the Aztecs.

“I wasn’t given an explanation other than there was no time on the clock,” Creighton coach Greg McDermott said. “They made no call on the floor but officiating is part of the game and we’re not gonna go there.”

Scheierman had tied the game at 56-all when he stole an inbounds pass and converted a layup with 34 seconds remaining.

Ryan Kalkbrenner scored 17 points and Scheierman and Kaluma had 12 apiece for the Bluejays, who went 2 of 17 from 3-point range.

The Aztecs, who got this far thanks to defense and physical play, held the Bluejays to 23 second-half points on 28% shooting as they won for the 14th time in 15 games. Creighton shot 40% overall.

San Diego State shot 38% but got clutch baskets from Nathan Mensah, whose jumper gave the Aztecs a 56-54 lead with 1:37 left, and Arop, who made two straight shots for a 54-50 advantage with 3:03 remaining.

Creighton, which beat San Diego State in overtime in the first round of last year’s NCAA Tournament, fell just short of joining Big East rival UConn in the Final Four.

The teams didn’t appear to share any hard feelings from last year’s meeting. They shared a round-trip flight to Hawaii last fall for the Maui Invitational, and there were no dustups during a tight, physical game in which no team led by more than eight points.

Divided Loyalties

Kaluma played against his brother, San Diego State’s Adam Seiko. Their parents sat a few rows up at midcourt, sitting quietly before joining Seiko to celebrate.

Big picture

Creighton’s offense started well enough as the Bluejays built a 33-28 halftime lead and extended their advantage to seven in the second half. But Creighton didn’t make a single 3-pointer after halftime.

San Diego State proved again that defense matters, especially since the Aztecs also scuffled for points. Their experience as depth showed as Mensah and Arop, who averaged just 6.1 and 4.5 points per game respectively, converted the last three baskets.