Two - against a 3-8 Miss State team and a 2-10 Ole Miss team
How many wins has BYU ever had against USC? zero
BYU has competed well against UW over the years but wins over ranked PAC 10 opponents are very rare for BYU (last one was in the 2009 LV Bowl, the one before that was against ASU in 1997).
I think ecstatic beyond belief would describe most BYU fans reaction if the Cougars could somehow manage to beat Utah this fall.