LaBrittney Jones scored 18 points and Arizona ended an 11-game losing streak with a 63-56 win over USC on Sunday in the regular-season finale at the Galen Center.
The Trojans (18-12, 6-12), who lost its fourth straight, is the eighth seed for the Pac-12 Conference tournament and meets No. 9 Washington State on Thursday in Seattle.
The Wildcats (12-18, 3-15) are the 11th seed and will face No. 6 Oregon.
Arizona used a 26-11 advantage in the second quarter to open a 38-22 lead.
The Trojans trailed by a dozen after three quarters but, after Arizona's Breanna Workman opened the fourth with a basket, reeled off 12 unanswered points to make it 55-53 on Alexis Lloyd's three-point play with 4:56 to play.
Keyahndra Cannon and JaLea Bennett each made two free throws in the last 18 seconds to ice it after USC made just one free throw in the final two minutes.