USCs first win at the Rose Bowl Stadium (or the Tournament of Roses Stadium, as it was then known) was against Idaho. The Trojans defeated the Vandals, 14-0, before a crowd of 12,500, on November 18, 1922. That was the first USC game against Idaho, as both joined the Pacific Coast Conference that year.
It was a transition year for USC: the first season that would conclude with a Rose Bowl game, the last season that would feature a game at Pomona, USCs first real big rival.