Center Deandre Ayton had 15 points and eight rebounds and Parker Jackson-Cartwright added 12 points for the Wildcats, who lost a 12-point lead in the second half before recovering.
Sedrick Barefield had 26 points, David Collette 14 and Justin Bibbins 10 for the Utes (13-8, 5-5 Pac-12). Utah had its three-game winning streak broken.
Jackson-Cartwright's jumper with 8:50 remaining gave Arizona (18-4, 8-1) a 65-54 lead before Utah responded to take a 66-65 lead with a 12-0 run buoyed by four Bibbins free throws and 3-pointers by Tyler Rawson and Parker Van Dyke.
After the teams traded baskets, Arizona regained the lead for good on Ristic's jumper with 2:31 remaining.
Ristic hit a 3-pointer on the next possession to make it 72-68, and his two free throws with 1:01 left boosted the advantage to 74-70.
Bibbins hit a 3-pointer with 4.3 seconds remaining to make it 74-73, and Trier ran into Bibbins and was called for an offensive foul as Arizona tried to inbound the ball, giving the ball to Utah and taking no time off the clock.
The Utes got the ball under the basket to Donnie Tillman, whose short shot was contested and did not draw iron. Arizona's Keanu Pinder grabbed the rebound and was fouled with three-tenths of a second remaining.
Pinder missed the free throw, but Collette could not get a shot off after getting the rebound.
Arizona made 11 of its first 16 shots from the floor and finished with a 64.4 field-goal percentage. The Wildcats were 11th in NCAA Division I with a 50.4 percentage entering the game.
Utah shot 44.4 percent but stayed in the game by making 18 of 21 free-throw attempts. Arizona was 6-of-11 at the line.
The Wildcats made 10 of 16 3-point attempts, including six of their first seven. Trier and Jackson-Cartwright had two apiece. Jackson-Cartwright has made eight 3-pointers in his past four games.
Barefield, a starter most of the season, has scored 14, 17 and 26 points while coming off the bench in the past three games. Collette posted a season-low four points while battling foul trouble in an 80-77 overtime victory over Arizona State on Thursday.
--Field Level Media
Utah | Arizona | |
Sedrick Barefield 26 | Scoring | Dusan Ristic 23 |
Justin Bibbins 4 | Assists | Parker Jackson-Cartwright 6 |
David Collette 6 | Rebounds | DeAndre Ayton 8 |
Sedrick Barefield 8 | Free Throws Made | DeAndre Ayton 2 |
David Collette 2 | Steals | DeAndre Ayton 1 |
Jayce Johnson 1 | Blocks | DeAndre Ayton 2 |