PROVO, Utah -- With leading scorer Jimmer Fredette slowed by strep throat and an allergic reaction, BYU (No. 23 ESPN/USA Today, No. 25 AP) had to rely on somebody else this time.
The Cougars overcame a tough game for Fredette, rallied late in the second half and then held off UNLV 77-73 on Wednesday night, using an 11-2 run to pull ahead and not allowing the Rebels to make a field goal over the final 5:55.
Noah Hartsock carried the Cougars through the first half and Jonathan Tavernari took over in the second, scoring 14 of his 17 points after halftime as BYU won the Mountain West Conference opener for both teams.
"They just competed," BYU coach Dave Rose said. "They knew it was time to win and they found a way."
Hartsock finished with 17 points, 13 in the first half as the Cougars shot 27 percent and made only two 3-pointers.
BYU (15-1) clinched it from the free throw line and beat UNLV for the first time in nearly two years, ending a three-game losing streak to the Rebels (12-3).
Tre'Von Willis led UNLV with 24 points.
"We've got to find a way to win those," Willis said. "That's the difference between winning the conference and not winning the conference."
BYU out rebounded UNLV 44-37 and made 19 of 24 from the free throw line while holding the Rebels to just 12 foul shots.
After shooting 27 percent in the first half with just two 3-pointers, the Cougars regained their touch in the second, going 14 of 27 and making 6 of 11 from beyond the arc.
"That game could have gone any way. We made one or two more plays that made the difference," said Tavernari, who led BYU with nine rebounds. "Our hearts were not fatigued. We had to step up and that's what we did."
Fredette played 25 minutes, wearing long sleeves under his jersey, but was obviously struggling from his illness and an allergic reaction to some of the medication he received. He was 2 of 10 from the field and finished with seven points, 14.6 below his average.
"He got winded early and just didn't have that same spark to him," Rose said. "Hopefully he can get back to normal as soon as possible."
UNLV had an early run to take the lead in the second half, then after BYU rallied to get back in it, the Rebels used their quickness and outside shooting to go up again 69-64 with about 5 minutes left, but that's when BYU took over with an 11-2 run.
Emery started it with two free throws, Michael Loyd Jr. leaped over everybody for a layup and then Tavernari hit a 3-pointer to put BYU up 71-69 with about 2:45 left.
Willis tied it with two free throws, the Loyd sped through the lane for another layup to put the Cougars back ahead. Willis saved the Rebels from a turnover on the next possession by running down a loose ball, but couldn't get to it after losing control with about a minute left as he and the ball went out of bounds.
"We got ourselves in position to do what we needed to do to close the game the right way, but just didn't do it," UNLV coach Lon Kruger said. "We have got to be strong on the road and tonight we just lost control at the end."
BYU led 33-32 at halftime despite making just 11 of 41 shots. The Cougars overcame their shooting woes with 14 offensive rebounds and by going 9 of 9 from the free throw line.
Hartsock got the last of the offensive boards when he tipped his own miss back in with one hand while drawing the foul with 38 seconds left. He hit the foul shot to complete the three-point play.
"He kept us in the game in that first half," Rose said. "We were having a difficult time finding points."
Mike Krzyzewski says he has good reason to be excited for next season thanks to a combination of Duke's incoming freshmen and a core of experienced upperclassmen.
Georgia guard Juwan Parker has been awarded a medical redshirt, leaving him with two years of eligibility, after missing the 2015-16 season with a partially torn Achilles tendon.
Forward Trevon Bluiett has withdrawn from consideration from the NBA draft and will return to Xavier for his junior season.