1987, 2002, and 2003. Auburn defeated USC in the 1987 Florida Citrus Bowl and USC won in the regular season in 2002 and 2003.
As of 10/10/10, California last beat USC on September 27, 2003. The final score was 34-31 in triple overtime; this was USC's only loss in the season where they won the AP National Championship, but...
Football
University of Southern California President: Steven B. Sample
George Tirebiter, the unofficial mascot of the University of Southern California in the 1940s