LAS VEGAS — Jimmer Fredette scored 21 points, Jonathan Tavernari had 19 points and 11 rebounds, and No. 25 BYU overcame a halftime deficit in an 80-69 victory over Air Force on Thursday in the Mountain West Conference tournament quarterfinals.

Lee Cummard scored 10 of his 16 points in the second half, adding eight rebounds and seven assists as the top-seeded Cougars (22-9) survived a scare from the surprising ninth-seeded Falcons, who went winless in 16 regular-season Mountain West games before beating Colorado State in Wednesday's play-in.

Anwar Johnson scored 16 of his 24 points in the first half for Air Force (10-21), which led 41-38 at halftime by outrebounding and outshooting the taller Cougars. The Falcons even kept it close until the final minutes, when Lamont Morgan Jr. and Tavernari hit key 3-pointers to finish off BYU's fifth straight victory.

BYU advanced to face the winner of UNLV's meeting with San Diego State, a quarterfinal between two teams probably needing a victory to get into the NCAA tournament.

The early quarterfinal at the Thomas and Mack Center wasn't the expected near-walkover for BYU, which grabbed a share of its third straight Mountain West regular season title and its first national ranking of the year with a strong surge to close the regular season — although the Cougs' five-point victory over Air Force last Saturday wasn't among their impressive moments.

BYU had won nine of 10 overall before heading to Las Vegas, where the Cougars lost to UNLV on Feb. 21.

Air Force clearly got an emotional boost from its win over Colorado State. The Academy had lost its previous 16 straight opening-round conference tournament games, including the 2004 opener as the top seed.

Andrew Henke scored 18 points with three 3-pointers and five assists, while Matt Holland and Grant Parker had 10 points apiece for the Falcons, who began the season 8-2.

Perhaps remembering the Cougars' struggles against Air Force last week, the BYU fans in attendance grumbled with nervousness when Air Force took a 13-8 lead on Trevor Noonan's 3-pointer with 13:40 left in the first half. Johnson was particularly relentless, scoring inside and out to push the Falcons ahead at halftime.

BYU regained the lead with a 15-6 run after halftime, although Air Force rallied back with help from the Cougars' spotty shot selection. The Falcons fell behind for good midway through the second half, but after Sammy Schafer's three-point play pulled them to 68-65 with 3:52 left, BYU scored the next seven points and hit enough free throws late to keep a comfortable lead.