EUGENE, Ore. -- Oregon quarterback Marcus Mariota rarely gets rattled. But he does get concerned.
Never mind that the second-ranked Ducks handily defeated Washington State 62-38, or that Mariota threw for two touchdowns and ran for another.
The sophomore quarterback was kicking himself for a pair of fumbles, both of which led to first-half touchdowns for the Cougars.
"I've got to take care of the ball better," he proclaimed after the game.
Mariota kicked things off with a 57-yard scoring dash on the first series of the game for the Ducks, who wore pink helmets, cleats and socks for Breast Cancer Awareness Month. Teammate Byron Marshall ran for 192 yards and three touchdowns.
Mariota's star has continued to rise as the Ducks (7-0, 4-0 Pac-12) have collected wins, and he is considered by many to be a leading Heisman Trophy candidate. The fumbles were his first turnovers this season, and he has yet to throw an interception.
"I'm just trying to handle it the best that I can," he said. "It's not just me that's doing well, it's the team."
Except for the fumbles, Mariota was his solid self, completing 23 of 32 passes for 327 yards.
Meanwhile, Washington State's Connor Halliday was breaking records.
Halliday completed 58 of 89 passes for 557 yards and four touchdowns for the Cougars (4-4, 2-3). His attempts broke the FBS-level record of 83 set by Drew Brees for Purdue on Oct. 10, 1998. His total attempts and completions also broke the Pac-12 records set by Arizona's Matt Scott last season, and his total yards set a Washington State record.
But Halliday also threw four interceptions, including one that was returned 51 yards for a touchdown by Terrance Mitchell early in the fourth quarter. The junior leads the nation with 17 interceptions.
"I knew going in, on about Monday of last week, that we were going to throw it a lot. I mean, nobody ever thinks 89 is going to be the number," Halliday said.
While Washington State pulled within 27-21 in the first half, Oregon cleaned up the mistakes in the second half and pulled away, racking up 719 yards in total offense. Freshman Thomas Tyner ran for 99 yards and two touchdowns.
The Ducks were coming off a 45-24 victory over Washington in Seattle last weekend. After Stanford's upset loss to Utah last week, undefeated Oregon is alone in first place in the Pac-12 North.
The Cougars were coming off a 52-24 loss to Oregon State in Pullman last weekend. The Beavers outscored Washington State 28-0 in the fourth quarter and Halliday threw three interceptions.
"One thing that is really impressive about Oregon is how decisively they play," coach Mike Leach said. "They're probably the most decisive team in how they play in the country."
Oregon remained without dynamic running back De'Anthony Thomas, who was in pads and practiced before the game but didn't play for the third straight game. Thomas, who has run for 338 yards and six touchdowns, has been out since his slipped on the rain-soaked turf at Autzen on the opening kickoff against Cal.
After Mariota's opening touchdown, Marshall plowed across the line for a 1-yard touchdown midway through the first to up Oregon's lead to 13-0. Halliday found Dom Williams in the corner of the end zone with an 11-yard scoring pass, but Marshall answered with a 26-yard scoring run to make it 20-7.
Tyner made an acrobatic catch to get to the Washington State 1, then powered into the end zone for the touchdown early in the second quarter.
Mariota was sacked and his fumble was recovered by Washington State, leading to Halliday's 22-yard pass to River Cracraft for the freshman receiver's first touchdown.
He was sacked and fumbled again on the next series and Xavier Cooper scooped up the ball and ran it in to narrow the score to 27-21 with 5:35 left before halftime.
"Our culture around here is always one play at a time," Mariota said. "Whatever happens you have to shake it off and move on."
Tyner scored on a 66-yard run for the Ducks before Andrew Furney kicked a 49-yard field goal for the Cougars as time ran out to make it 34-24.
Mariota found Keanon Lowe with a 10-yard scoring pass and Marshall scored on a 30-yard run in the third quarter before Mitchell's pick six early in the fourth.
Halliday's passing yards surpassed Alex Brink's Washington State record of 531 against Oregon State in 2005.
"That's crazy. I don't think I could throw that many passes. My arm would hurt," Cougars defensive lineman Xavier Cooper said.
The Ducks extended their winning streak over the Cougars to seven straight.
Washington State defeated a ranked opponent earlier this season when they beat then-No. 25 USC 10-7, although it was before the Trojans fired head coach Lane Kiffin. The Cougars have not defeated a team in the top five since 2003, when they downed No. 5 Texas 28-20 in the Holiday Bowl.
Oregon planned to auction a number of the pink helmets off after the game to raise money for Kay Yow Cancer Fund, named after the North Carolina State women's basketball coach who died of breast cancer in 2009.