CORVALLIS, Ore. -- Michael Doctor summed up Oregon State's mentality in the fourth quarter against No. 6 Arizona State.

"We knew we didn't have anything to lose," he said.

Doctor returned an interception 35 yards for a touchdown with 1:38 left to seal the Beavers' 35-27 upset win over the Sun Devils (No. 7 AP) on Saturday night.

Oregon State had pulled in front 28-27 on Sean Mannion's 66-yard touchdown pass to Jordan Villamin with 10:55 to go. Mannion finished with 251 yards passing and two touchdowns as the Beavers (5-5, 2-5 Pac-12) snapped a four-game losing streak.

Afterward, the crowd that stuck around despite the sub-freezing temperatures rushed the field.

Mannion, a fifth-year senior who came back to the Beavers rather than bolt for the NFL, was asked if it was the high point of this career.

"Absolutely, absolutely," he said. "I put this as high as anything."

The Sun Devils (8-2, 5-1) snapped a five-game winning streak. The loss to the slumping Beavers hurt Arizona State's shot at a second straight berth in the Pac-12 championship game.

"Heck, we're still playing for a conference championship. We've still got an opportunity to win the South," Arizona State coach Todd Graham said. "Win the next two games, I believe we'll be there Dec. 5th. That's all we can do. We can't worry about anything else."

Taylor Kelly threw for 264 yards and two scores for the Sun Devils. He was intercepted twice as temperatures dropped into the upper 20s.

"Our plan was to win the national championship," Kelly said. "We didn't come out and execute."

The Mike Riley-led Beavers have a tradition of pulling off surprise wins against high-ranked opponents at home. In 2012, the Beavers upset No. 13 Wisconsin -- which went to the Rose Bowl that season -- at Reser. In 2008, the Beavers were 26-point underdogs when they knocked off then-No. 1 USC 27-21 on a Thursday night in Corvallis. Two years earlier, Oregon State topped the then-No. 3 Trojans at Reser 33-31.

"It's great to see us just cut loose and play football," Riley said about the latest upset.

Villamin had four catches for 127 yards, while Terron Ward ran for 148 yards and an early touchdown for the Beavers. Mannion reached 80 career touchdown passes to move past Derek Anderson (2001-04) for the Oregon State record.

The Beavers struck first, scoring in the first quarter on Storm Wood's 78-yard run. It was the longest touchdown play of the season for Oregon State and longest of Woods' career. It was also the longest run for the Beavers since 2002, when Steven Jackson ran 80 yards against UCLA.

Arizona State's Damarious Randall intercepted Mannion and returned the ball 30 yards to the Oregon State 18, but the Sun Devils settled for Zane Gonzalez's 28-yard field goal to narrow the margin to 7-3.

Oregon State answered with Ward's 66-yard touchdown run. It was also the longest of his career.

Before the first quarter was over, the Sun Devils scored on Kelly's 17-yard scoring pass to D.J. Foster to close to 14-10.

Oregon State had eclipsed its season high for rushing with 183 yards on the ground in the first quarter alone. The Beavers finished with 247 yards rushing.

Arizona State pulled ahead 17-10 on Kelly's 46-yard scoring pass to Kody Kohl. Antonio Gongino's 36-yard fumble return for a touchdown, following the Sun Devils' sack of Mannion, extended the lead to 24-14 before the half. It was their fourth defensive touchdown in four games.

Mannion found Victor Bolden in the end zone with a 20-yard scoring pass to narrow it with 3:19 left in the third quarter.

Gonzalez made a 29-yard field goal with 12:43 left to give Arizona State a 27-21 lead before Mannion's TD pass to Villamin gave the Beavers the lead.

Oregon State punted on fourth-and-1 at the Arizona State 45 with 2:52 left, eliciting boos from the crowd. But Arizona State's ensuing drive ended with Doctor's interception.

The Sun Devils were coming off a 55-31 victory at home over Notre Dame last weekend.

The Beavers were coming off a disheartening 39-32 loss at home to Washington State which dropped them into the basement of the Pac-12 North.

Last season, Robert Nelson intercepted Mannion and ran back 23 yards for the touchdown in the fourth quarter of Arizona State's 30-17 victory over the Beavers in Tempe. Mannion threw for 320 yards and two scores but was intercepted four times in that game.