PROVO, Utah — Never mind if Cody Vaz hadn't taken a snap since 2010, or started a game since he was in high school.

PROVO, Utah — Never mind if Cody Vaz hadn't taken a snap since 2010, or started a game since he was in high school.

The Oregon State backup-turned-starter made it look easy in Saturday's 42-24 win over Brigham Young, passing for three touchdowns and 332 yards against a defense rated fifth in the nation.

What impressed teammates most wasn't his 59-yard completion to Brandin Cooks, or 29-yarder to tight end Connor Hamlett.

It was the block he made on a BYU defensive lineman that paved the way for Markus Wheaton to score on a 12-yard fourth-quarter reverse that bumped No. 10 Oregon State's lead to 11 points with 5:30 remaining.

"I loved that," said Wheaton, who also caught a pair of first-quarter TD passes from Vaz. "He got me into the end zone and put six points on the board for us. He's not scared to do stuff like that for us. That's why he's a great quarterback."

Until a week ago, Vaz was the unheralded backup to sophomore sensation Sean Mannion.

Then Mannion injured his left knee, thrusting the 6-1, 198-pound junior into the lineup, on the road, against a "blackout" crowd and a BYU team donning black uniforms for the first time in the modern era.

"I knew all along that Cody is a pretty good player, but I also knew this is a pretty hard venue to step into," Oregon State coach Mike Riley said. "I thought guys helped him out and made plays."

Vaz came out firing, completing his first five passes for 75 yards, capped by a 11-yard TD pass to Wheaton. He tossed a 24-yard scoring strike to Wheaton with 3:01 left in the quarter for a 14-7 Oregon State lead.

By the end of the first quarter Vaz was 8 of 10 for 153 yards with two TDs and a passer rating of 274.5.

"We have so many playmakers and I just have to get the ball into their hands," said Vaz, who completed 20 of 32 passes. "I knew I was capable of playing that way and I knew I had to come out and calm this place down, because it was a little rowdy. But this was a team effort."

Oregon State is 5-0 for the first time since 1939, while BYU fell to 4-3, and now must take on another top-10 team in Notre Dame on the road.

While Mannion is out indefinitely, Vaz still has the surrounding cast, and Saturday they came up big.

Cooks caught eight passes for 173 yards for the Beavers.

"Cody was just great at putting the ball where I could make the play and I couldn't let Cody down," said Cooks.

The Beavers also got some help on the ground, gaining 118 yards —double what BYU had been allowing.

Storm Woods and Malcolm Agnew led the way, with Woods scoring on a 16-yard third-quarter run for a 21-14 lead.

Vaz's third TD pass was pure luck as BYU linebacker Kyle Van Noy tipped it at the line. Tight end Colby Prince grabbed it in the end zone for a touchdown while surrounded by three defenders.

It gave Oregon State a 28-21 lead with 14:48 remaining.

"It was just kind of a bang-bang thing and luckily it fell into Colby's hands," Vaz said. "It was kind of scary seeing that ball float in the air, but luckily we came up with it."

A 35-yard field goal by Justin Sorensen pulled BYU within 28-24 with 8:55 left.

That's as close as the Cougars would get.