CORVALLIS, Ore. -- Riley Nelson threw for 217 yards and three touchdowns and rushed for 87 yards to lead BYU over Oregon State 38-28 on Saturday.
Cody Hoffman had nine receptions for 162 yards and a TD for the Cougars (5-2).
Sean Mannion was 27 of 43 passing for 306 yards for Oregon State (1-5) but was intercepted twice, bringing his season total to nine.
BYU has won four straight. It is 3-0 since Nelson replaced Jake Heaps in the middle of a 27-24 win over Utah State on Sept. 30.
Michael Alisa rushed for 84 yards as the Cougars compiled 282 as a team. They averaged 116 yards on the ground in their first six games.
BYU was 6 for 6 in the red zone and maintained control of the game despite three turnovers.
The Cougars took a 14-0 lead on touchdown runs by Alisa and JJ Di Luigi. Oregon State tied the game after a 1-yard touchdown run by Mannion and Jordan Poyer's 51-yard interception return for a score.
Meanwhile, linebacker Brandon Ogletree wreaked havoc on the Oregon State offense, intercepting a pass and forcing two fumbles on three straight possessions.
Oregon State hoped to the return of tailback Malcolm Agnew would boost its struggling running game, but the team managed just 59 yards on the ground.
It was a victorious homecoming for Cougars head coach Bronco Mendenhall, who played for the Beavers in 1986-87 and served as defensive coordinator under then-Oregon State coach Jerry Pettibone in 1995-96.
Oregon State defensive tackle Castro Masaniai fractured his fibula in the first half.
Nike Men's Oregon State Beavers Football Icon Legend Black T-ShirtShop
SEC Network's Maria Taylor, Marcus Spears and Kevin Weidl discuss the fit for QB Brandon Allen at Jacksonville and RB Jonathan Williams at Buffalo.
SEC Network's Maria Taylor, Marcus Spears and Kevin Weidl discuss the former Mississippi State QB's potential with the Cowboys.
SEC Network's Marcus Spears and Kevin Weidl discuss the SEC players that will have the biggest overall impact in the NFL.
SEC Network's Marcus Spears and Kevin Weidl break down the best fits for offense and defense, and players with the most upside from Day 3 of the Draft.
The Browns drafted former Arizona LB Scooby Wright III in the seventh round of the NFL draft, and he celebrated by jumping into the pool fully clothed.
Oregon's Pharaoh Brown once faced amputation for a horrific leg injury. But he has come all the way back and starred in Oregon's spring game.