Solomon Hill scored 13 points and Brandon Ashley chipped in with 11 as the Wildcats (17-2, 5-2 Pac-12) bounced back from a Thursday loss to UCLA.
Arizona unleashed a stifling defense, holding the Trojans to 28.1 percent shooting from the floor while producing 16 turnovers.
The Wildcats took control early, jumping out to a quick 18-4 lead and never looked back.
Jio Fontan's nine points paced the Trojans (8-13, 3-5), who fell to 1-3 under interim Coach Bob Cantu.
Beautician charged with giving client fatal silicone butt injection
Duggar sisters unveil Christian dating rules in new book