Boatright has made 29 of 53 3-point attempts in his last five games but the Utes usually had a defender draped on him and limited his attempts.
Van Dyke’s 3-pointer gave Utah a 76-61 lead with 3:42 remaining but the Utes, who have struggled with the press at times this season, had a couple turnovers that allowed the Trojans to draw within single digits. It might have been even tighter but the officials withdrew an offensive foul on Novak Topalovic after video review with 2:09 left.
Utah led 55-48 before going on an 11-2 run that was capped with an alley-oop and dunk from Tillman to Allen. The Utes led 66-50 with 10:06 to play as the crowd roared.
Jayce Johnson, Utah’s usual starting center, was out with an ankle issue but the Utes dominated in the paint and outrebounded the Trojans 32-23.
The Utes only trailed in the first minute and outscored the Trojans 12-0 in second-chance points and a 9-0 in fastbreak points in the first half.
USC’s Jonah Mathews was carried off the court after suffering a leg injury near the end of the first half but returned to play in the second half and finished with 10 points.
USC: The Trojans are limping to the finish. They had been betrayed by horrid free-throw shooting in their prior two outings but this one came down to being a step slow to loose balls and rebounds as they shot 55.6 percent from the field and 70 percent from the line.
Utah: The Utes made a strong play for a top-four finish and a bye in the Pac-12 tournament with one game left. The Utes looked as fluid on offense as they have for several games and limited their scoring droughts with good shooting.
USC: Plays its final regular-season game at Colorado on Saturday.
Utah: Caps the regular season with UCLA at home on Saturday.