Arizona jumped out to the early lead when sophomore BROOKE McMANUS took a shot which bounced off the right post, then junior JILL MICONE collected the rebound and notched her second goal of the year at the 8:09 mark.
USC notched the equalizer at 70:25 after Christina Kushnir sent one in from seven yards off a double assist by Isabelle Harvey and Susie Mora. Neither team was able to score in the remaining regulation time.
Harvey was responsible for the gamewinner, converting a penalty kick at 97:25 to help USC to its first-ever NCAA tournament appearance in the program's six-year history.
Arizona wraps up the year with a 3-12-2 overall record and an 0-8-1 mark in Pac-10 play. USC ends regular season at 13-6-1 overall and 7-2-0 in the Pac-10.