" USC is 18-59 all-time against Stanford after falling 6-1 to the Cardinal last season in Pac-10 play at Marks Stadium. USC's last win over Stanford was a 5-2 victory in 2009 in Los Angeles. It was USC's first win over Stanford in 23 years, snapping a 50-match losing streak to the Cardinal."
Well that USC win over Stanford no longer counts
because it was vacated after USC was found guilty with lack of institutional control.
USC still has a losing streak against Stanford for over 25 years and 55-matches.