Posted by ESPN.com's Ted Miller
LOS ANGELES -- Just like that, USC asserts itself.
Then defensive tackle Jurrell Casey put an exclamation point on a three-and-out with a sack, forcing the Spartans to punt from their endzone.
And then Allen Bradford goes 43 yards a touchdown, a career-long run that made it 21-3.
It appears that USC's backfield has a big three: Joe McKnight, Johnson and Bradford. They've combined for 131 yards rushing. C.J. Gable is the most obvious guy not getting carries.
And the USC defense is starting to dominate the line of scrimmage. The Spartans only have 20 total yards in the second quarter.