LAS VEGAS — Kawhi Leonard scored 16 points, grabbed a career-best 21 rebounds and sank all eight of his free throws in the final two minutes as San Diego State fended off UNLV 55-45 to win the Mountain West Conference title today.

The fourth-seeded Aztecs (25-8) earned the league's automatic NCAA bid, although third-seeded UNLV also burnished its NCAA credentials during the week.

The Runnin' Rebels (25-8) hope to join San Diego State, No. 8 New Mexico and No. 14 BYU in the field that's announced Sunday.

San Diego State upset New Mexico in the semifinals, the highest ranked team the Aztecs have ever beaten away from home, and sealed its fifth straight postseason berth — a first in the program's 89-year history.

Leonard, who averaged 9.5 rebounds in the regular season, finished with 39 rebounds in 72 hours and was named the tournament's most valuable player.

But he sealed the title with his prowess and poise at the line.

His two free throws with 1:54 left gave San Diego State a 48-42 lead, and he made six more in the final 54 seconds to hold off the Runnin' Rebels, who got 11 points each from Tre'Von Willis and Oscar Bellfield.

D.J. Gay added 11 points for San Diego State, which lost 52-50 to Utah in last year's title game.

Both teams were worn out after upsetting ranked teams in emotional, hard-fought semifinals at the Thomas & Mack Center on Friday night, the Aztecs dispatching top-seeded New Mexico and UNLV ousting BYU, the tournament's second seed.

The toll of those taxing wins showed up Saturday afternoon as both teams struggled to find an offensive rhythm. Time and again, shots that were falling a night earlier clanged off the front of the iron.

It took a flurry of baskets in the final two minutes of the first half for the Aztecs to take a 25-22 lead into the locker room.

Billy White, who missed nine of his first 10 shots, sank back-to-back buckets to give San Diego State a 43-40 lead, and Gay split a double team with a 3-pointer that made it a six-point game with 5½ minutes remaining.

Willis ended a nearly five-minute drought with a bucket that made it 46-42 with 2:54 left, but with Leonard perfect at the foul line down the stretch, the Runnin' Rebels didn't have a chance.