Even the much-maligned USC secondary played well, picking off three Sean Mannion passes as the Trojans defense gave up only one touchdown.
The interceptions were made by Josh Shaw, Dion Bailey and Kevon Seymour. Shaw's and Bailey's came in the end zone and near the goal line.
Mannion had 30 touchdown passes and only three interceptions in 391 passes coming into the game. USC matched that in 40 passes on Friday night.
Mannion, who was averaging 408 yards passing a game, finished with 277 on Friday, completing 26 of 45 passes.
USC improved to 6-3 overall -- 3-1 with Orgeron in charge -- and 3-2 in Pac-12 Conference play. Oregon State fell to 6-3 overall, 4-2 in conference play.
The Trojans outgained the Beavers, 489 yards to 369, and had a 242-92 edge in rushing yardage.
Silas Redd ran for 140 yards in 22 carries for USC, and Buck Allen had 133 yards in 16 carries, including scoring runs of nine, 18 and 52 yards.
The Trojans also got production out of Marqise Lee, who returned to the lineup after missing last week's game against Utah with a knee injury.
Lee hauled in a 71-yard touchdown pass on USC's first play from scrimmage and finished with five catches for 105 yards.
Oregon's State only touchdown on offense came on a 27-yard pass from Mannion to Brandin Cooks. It was Cooks' nation-leading 14th touchdown reception of the season. However, Cooks wasn't really a factor. He came in averaging 10.6 catches and 157 yards a game, but was held to two catches for 40 yards by USC.
USC quarterback Cody Kessler completed 17 of 21 passes for 247 yards and a touchdown. About his only mistake was a pass he threw into triple coverage that was intercepted and returned 42 yards for a touchdown by Ryan Murphy early in the second quarter.
Oregon State didn't score again.
Sean Mannion, who had thrown 391 passes in eight games before this one, with only three interceptions, has thrown as many interceptions tonight in 40 passes.
This one was pulled in by Kevon Seymour, the cornerback beat early in the game on what was Oregon State's only touchdown on offense.
USC leads, 31-14, with 4:04 left in regulation.