Caleb Williams threw two touchdown passes to Mario Williams and No. 6 Southern California shut out Washington State in the second half of a 30-14 victory Saturday night. Travis Dye rushed for 149 yards and a touchdown for the Trojans (6-0, 4-0 Pac-12), who stayed unbeaten in coach Lincoln Riley's first season. USC hadn't started a season 6-0 since 2006, near the height of coach Pete Carroll's powerhouse era. Caleb Williams went only 15 of 29 for 188 yards, but made big throws when necessary in an up-and-down performance. The Trojans didn’t need their quarterback to be brilliant this time, with Dye and the offensive line doing much of the damage in a workmanlike second half.Cameron Ward passed for 172 yards while hitting Robert Ferrel and Nakia Watson for touchdowns for the Cougars (4-2, 1-2), who remained winless at the Coliseum since 2013. Washington State fell short of its second road victory over a Top 25 team this season when its offense bogged down on seven consecutive scoreless drives to end the game. Although USC's defense somehow didn't add to its 15 takeaways this season, the Trojans impressively shut down an opponent that had scored 107 points in its previous three games. Washington State didn't score in the final 43 minutes, and Tuli Tuipulotu got three of the Trojans' five sacks. USC even persevered through the absence of three significant players. Biletnikoff Award-winning receiver Jordan Addison left the Trojans' lineup during the second half with an undisclosed injury. USC already was without top linebacker Shane Lee due to injury, and it lost top safety Calen Bullock to a targeting call decided by video review in the second quarter. - USC/AP College Football