Oregon State came into Saturday's Pac-12 opener with an already-porous defense, and a banged-up secondary didn't help matters. A matchup with No. 21 Washington State and its relentless Air Raid attack only exacerbated the problems.

Luke Falk threw for 396 yards and a career-high six touchdowns on a day filled with personal-best achievements as the Cougars rolled to a 52-23 win over the ailing Beavers at Martin Stadium in Pullman, Wash.

Falk, who completed 37 of 49 attempts to nine different receivers, tied the program's single-game record on a 10-yard touchdown to Kyle Sweet to extend the lead to 42-16 with 56 seconds left in the third quarter.

"(Falk) utilized a lot of players out there, looked sharp," Cougars head coach Mike Leach said. "Other than the last two series, I thought he looked very sharp."

Five of the senior's six touchdowns were caught by Tavares Martin Jr. and Isaiah Johnson-Mack. Martin Jr. led all receivers with 10 catches for a career-high 194 yards and three TDs. Johnson-Mack added nine catches for 79 yards -- both career highs -- and two scores.

The Beavers (1-3, 0-1 Pac-12), who trailed by 19 at the half, pulled to within 28-16 on Ryan Nall's second touchdown, a 45-yard run midway through the third quarter. Nall finished with 118 yards on 15 carries.

Falk answered and set another Washington State record on a 57-yard catch-and-run for Martin Jr.'s third touchdown, pushing the lead to 35-16 with 4:19 left in the quarter. Falk became the first Washington State quarterback to throw at least five touchdowns on eight different occasions.

"He can do a lot of things," Falk said of Martin Jr. "He's got good hands, he can make people miss."

A 40-yard fumble return touchdown by Frankie Luvu gave Washington State (3-0, 1-0) its largest lead at 49-16. It is the Cougars' first 3-0 start since 2005.

In a scary moment, Beavers quarterback Jake Luton was knocked out of the game after a blow to the head by Jalen Thompson on a 9-yard run with 11:40 to play. After a 10-minute delay, Luton was carted off the field and gave a thumbs-up before entering the tunnel.

"His health is bigger than (the result)," Nall said. "We're gonna pray for him and his family.

"I don't know exactly what (the injury is), but they told us that he's gonna be OK."

Luton finished 22 of 35 for 179 yards passing.

With the game out of hand, head coach Gary Andersen said the decision to keep Luton in the game was an effort to "get the offense better" with more reps. Andersen said he felt "helpless" when Luton was carted off.

"That's where we are right now as a program," Andersen said. "Our kids can use every rep that they can get."

Martin and Johnson-Mack were the beneficiaries of a balanced first-half passing attack -- and one big miscue -- as the Cougars took a 28-9 lead into the locker room. The receiving duo hauled in two touchdowns apiece, including a pair inside the final two minutes.

Trailing 21-9, Oregon State punter Nick Porebski fumbled the snap and Cougars senior Gerard Wicks recovered at the Beavers 26 with 58 seconds left. Martin's 21-yard catch on the ensuing play set up a pair of 2-yard Johnson-Mack catches, including a touchdown with four seconds remaining.

Oregon State's defense could only stay within striking distance for so long while playing without starting cornerback Dwayne Williams (ACL, out for the season) and backup Jaydon Grant (shoulder).

Facing an opponent ranked 115th among 129 FBS teams in total defense, Washington State gained just 57 of its 491 yards in the opening quarter.

"We tried to do too much, we tried to be too perfect," Leach said.

Trailing 7-0, the Beavers hurt themselves with two penalties for 25 total yards and Artavis Pierce stepped out of bounds to shave nine yards off an initial 20-yard catch. Oregon State pinned a punt at the 1 and the defense rewarded the effort.

Jamal Morrow caught a tipped pass in the end zone and Shawn Wilson swooped in for the safety to cut the Beavers' deficit to 7-2 at the 4:20 mark.

NOTES: Luke Falk was denied the chance to set a single-game touchdown record. He was relieved by backup Tyler Hilinski with less than seven minutes to play. ... Cougars WR Tavares Martin Jr. topped 100 yards for the second time in his career. He last reached the mark against Boise State in 2016. ... Beavers S Jalen Moore served a first-half suspension stemming from a targeting ejection last week. On the plus side, WR Seth Collins (game-time decision) returned after missing the first three games with a broken finger and caught a fourth-quarter touchdown. ... LB Shemar Smith collected Oregon State's first sack of the season in the defense's first drive of the game. ... Ryan Nall's two touchdowns moved him into a tie for ninth on Oregon State's all-time list.