Williams, a sophomore from Florida, had a sack and forced a fumble that was recovered by Uko and led to a second-quarter touchdown.
Uko also had a sack.
Williams played despite a shoulder injury that he suffered during training camp and aggravated Nov. 1 at Oregon State.
Linebackers J.R. Tavai and Michael Hutchings led the Trojans with six tackles.
Linebacker Hayes Pullard had four tackles and linebacker Devon Kennard was one of seven Trojans with three.
USC plays UCLA this coming Saturday at the Coliseum.