USC (17-12, 10-7 Pac-12) led 32-22 at halftime, but Utah (11-17, 4-13) opened the second on a 12-5 run to pull within 37-34.
The Trojans answered with an 11-2 run to go ahead 48-36 on Desiree Bradley's 3-pointer with 12:39 to play. USC led by no less than seven points from there.
Brianna Barrett had 13 points and six assists, Alexyz Vaioletama had 11 points and Cassie Harberts 10.
Michelle Plouffe had 27 points and 18 rebounds with two steals and two blocks for the Utes. But she was just 8 of 24 from the field and 0 of 5 from 3-point range.