Trojans finding rhythm

Posted by ESPN.com's Ted Miller

LOS ANGELES -- Just like that, USC asserts itself.

Matt Barkley completes two passes for 50 yards to Damian Williams, which sets up Stafon Johnson's second TD run.

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.