ANAHEIM, Calif. (AP) -- Utah State is in the NCAA Tournament for the third time in four years after beating the most surprising team in the Big West Conference tournament.

Cardell Butler made four free throws in the final seconds and scored 17 points to lead the third-seeded Aggies to a 57-54 victory over Cal Poly-San Luis Obispo for the Big West tournament title Saturday night.

Utah State (24-8) will enter the NCAAs with a five-game winning streak.

"Our confidence is sky-high right now,'' said the Aggies' Desmond Penigar, who scored 13 points and was voted the tournament's most valuable player. Spencer Nelson added 11 rebounds and nine points.

Cal Poly (16-14) was picked to finish no higher than sixth in the Big West before the season, and had never won a game in an NCAA Division I conference tournament before this year.

"Their defense picked up a lot,'' Penigar said. "They play a lot of team ball, and they play with a lot of heart. We barely beat them the last time we played them, and we knew it was going to be a tough game.''

The teams were tied at 52 when Spencer Nelson's free throw put Utah State ahead by one point with 3:23 to play.

Cal Poly missed four shots from the field in the next 2:36.

Butler was fouled by Steve Geary with 15.1 seconds to go and made two free throws to give Utah State a 55-52 lead.

Cal Poly's Jason Allen made two free throws to make it 55-54 with 10 seconds left. But Butler responded with two more foul shots with 8.1 seconds left. Allen's 3-point attempt with 2 seconds left missed.

Allen led all scorers with 21 points and Varnie Dennis had 19 points for the fourth-seeded Mustangs.

"It just slipped through our hands,'' a dejected Dennis said. "I'm still in a state of shock.''

Butler, Allen and Dennis joined Penigar on the all-tournament team, which included Utah State's Mark Brown and UC Irvine's Mike Hood.