SALT LAKE CITY -- Kelly Olynyk scored 19 points and made a key basket with 42.7 seconds left to lift No. 2 Gonzaga to a 70-65 victory over BYU on Thursday night.
Gary Bell Jr. had 15 points and Elias Harris added 11 as the Zags (28-2, 15-0 West Coast Conference) notched their fourth straight victory over the Cougars.
Tyler Haws had 19 points to lead BYU (20-9, 9-5) and senior center Brandon Davies chipped in 12 points and 11 rebounds for his ninth double-double of the season.
Gonzaga broke open a tight game early in the second half. The Zags went up 45-36 after Kevin Pangos drilled a 3-pointer to cap a 10-5 run. Then a flagrant foul by Bronson Kafusi on Olynyk turned into a four-point swing that boosted the Zags to a 54-43 lead with 10:51 left.
That set the stage for a huge rally from the Cougars. Brock Zylstra and Haws combined to drill 3-pointers on three consecutive possessions, fueling a 17-6 run that erased Gonzaga's lead. Davies hit a pair of free throws to cap the run and tie it at 60-60 with 4:10 left.
BYU could not take the lead when it mattered, though. Harris hit a free throw and added a jumper to give the Zags a 63-60 lead. Davies answered with a jumper to cut to one again. But Olynyk converted his own jumper and Pangos drained a pair of free throws in the final minute.
The Cougars had one final chance after Haws made three free throws with seven seconds remaining. But Harris made three free throws in the final seconds to secure the victory.
BYU endured a sluggish start against the Zags' imposing defense. The Cougars missed eight of their first 10 shots. Making matters worse, Davies went to the bench with two fouls at the 17:27 mark of the first half.
Without Davies on the floor, Gonzaga attacked BYU around the basket and on the perimeter. Bell did the most damage on the outside, hitting three consecutive 3-pointers over a three-minute span to push Gonzaga out to a 23-14 lead.
Davies came back in at the 11:07 mark, and his return gradually shifted momentum back in the Cougars' favor. He hit a pair of free throws and threw down a dunk to spark a 9-2 run to bring BYU to within two at 25-23 with 6:30 left in the half.
The Cougars pulled to within a point with 2:09 left after Matt Carlino put back his own missed jumper to make it 30-29. A pair of shooting fouls by Nate Austin helped the Zags survive the charge. Drew Barham and David Stockton combined to convert five free throws and create a four-point cushion for Gonzaga going into the locker room.
NOTES: This was just the second game between Gonzaga and BYU in Provo. The Cougars won that meeting last season, 83-73. ... The Zags are off to their best start since 2003-04, when Gonzaga won a school-record 21 straight. ... BYU has the second-longest current streak of 25-win seasons in the country (six), behind only Kansas.