Lauri Markkanen led the Wildcats (5-0) with 16 points and nine rebounds, while Kobi Simmons had 14 points on seven shots, hitting all three of his 3-point attempts.
Dusan Ristic added 12 points and four rebounds.
The Broncos made it a one-point game with about four minutes to go, but Arizona held on for the win. Simmons, the player of the game, hit a step back jumper for the dagger.
The victory means Arizona will face the Butler Bulldogs to wrap up its stay in Sin City. Butler (5-0) beat Vanderbilt on Thursday 76-66 to clinch its spot in the title game.
The Bulldogs’ leading scorer is Kelan Martin, a 6-foot-7 junior who is averaging 16.2 points per game.
Butler also has three other players — forward Andrew Chrabascz, guard Avery Woodson, and guard Kamar Baldwin — averaging roughly nine points per contest.
Tyler Lewis, a senior guard, is leading the team in assists, posting 5.5 per game. He is also scoring 6.8 points per contest.
Baldwin, a 6-foot freshman, is the only one among the five players that is not a junior or senior.
“They have some things we don’t,” Arizona head coach Sean Miller said of Butler, via the Arizona Daily Star. “They have experience. They have veteran leadership…and when you watch them in November, they’re a little further along than a lot of teams.”
Kenpom.com ranks Butler as the No. 19 team in college basketball. Arizona is No. 20.
The Bulldogs are shooting a scorching 50.5 percent from the field this season and 38.3 percent from 3. Opponents are shooting 40.4 and 34 percent, respectively.
The last matchup between Arizona and Butler was in 2001 when the Wildcats eliminated the Bulldogs in the second round of the NCAA Tournament.
Arizona won 73-52, with Gilbert Arenas, Jason Gardner, Loren Woods, and Michael Wright scoring in double figures for the Wildcats.
Friday’s matchup will be the fourth time in history these teams have squared off. Arizona has won all three previous meetings.
Arizona guard Allonzo Trier sat out Thursday against Santa Clara (unspecified reasons) and did not travel with the Wildcats to Las Vegas.
The sophomore has missed all five of Arizona’s games this year and will miss his sixth game on Friday when the Wildcats face the Bulldogs.
The UA has not commented on Trier’s status and a potential return date is unclear.
The Wildcats, down to eight healthy scholarship players, will have their depth tested Friday in what is their second game in as many days.
How to watch
Time: 8:30 p.m. MST
TV: Fox Sports 1
Announcers: Justin Kutcher and Bill Raftery
Radio: Arizona IMG Radio Network
Stream: Fox Sports Go
You can follow Ryan Kelapire on Twitter at @RKelapire