EUGENE — The Oregon Ducks knew Oregon State would give its best shot in the Civil War.
The Beavers, looking for their first and only conference win, mounted a furious second-half rally and came within three points of the Ducks twice in the fourth quarter. But ultimately No. 18 Oregon prevailed 52-42 Friday in the 119th meeting between the teams.
"We knew it would be a heavyweight fight. Those guys, they're right up the road. All week people kept hearing about their record. But since last weekend we knew that record wouldn't mean anything. Our record wouldn't mean anything," said Oregon receiver Bralon Addison, who caught three touchdowns and ran for another.
Vernon Adams threw for 366 yards and those three touchdowns to Addison as the Ducks won their sixth straight. Addison finished with eight catches for 106 yards.
Royce Freeman ran for 167 yards and two touchdowns for the Ducks (9-3, 7-2 Pac-12), who will now wait to see how the postseason bowl picture shakes out. Stanford will represent the Pac-12 North in the conference championship game.
It was the ninth straight loss for the Beavers (2-10, 0-9), the most since 1995 when they lost 10 in a row. Oregon State did not win a conference game for the first time since 1997.
The Beavers did not make it easy for the Ducks. Victor Bolden ran 78 yards on a punt return for the touchdown to narrow the score to 38-35 early in the fourth quarter. Adams answered on the next drive with a 4-yard touchdown pass to Addison.
Then Ryan Nall broke away for a 66-yard scoring run to draw the Beavers close once more with 7:05 to go. Again Adams answered with a 24-yard TD pass to Addison for the final margin.
Nall finished with a career-high 174 yards rushing and a score for the Beavers, who had averaged just 14.7 points during the losing streak going into Friday's game.
"I don't know if I'll ever be surprised by a football game, but I was proud of them. Those kids deserved to end the year with an opportunity to play in a big-time game," Oregon State coach Gary Andersen said. "Quite frankly, I'm sure nobody gave them a chance but themselves and the people that are closest to us, and they battle like crazy. It was a good feeling and it was something they can build on."
Oregon State's Seth Collins, who missed four games with a left knee injury, returned and ran for three touchdowns while sharing quarterback duties with first-time starter Marcus McMaryion.
Adams, a senior transfer from Eastern Washington, broke a finger in the opener against his former team and struggled before the Ducks sat him down. But his return coincides with Oregon's six-game winning streak and he's thrown for 300 or more yards in four of those games.
Adams had faced the Beavers before, back in 2013 when Eastern Washington upset the then-No. 25 Beavers 49-46. He threw for four touchdowns and ran for two more and the Eagles became just the third FCS team to beat a ranked FBS team.
The mobile Collins, who still led the team in rushing despite his injury, scored on a 4-yard run to give the Beavers the early 7-0 lead. Andersen said last week said Collins would sit the rest of the season, but the true freshman quarterback returned to practice this week — at receiver.
Collins was the starter at QB at the start of the season, with redshirt freshman McMaryion serving as backup. Nick Mitchell, also a redshirt freshman, later played himself into the backup role.
Mitchell started while Collins was sidelined, but this week Andersen announced McMaryion would get his first career start, and hinted that Collins would play.
The Beavers' early lead was short-lived and on the next series of the game Addison ran for a score to tie it.
Taj Griffin added a 14-yard touchdown run and Aidan Schnieder kicked a 25-yard field goal to extend the Ducks' lead to 17-7.
Freeman rushed for a 3-yard touchdown before Adams' 37-yard pass to Addison — which extended Oregon's streak of games with at least one touchdown pass to 80. The TD gave the Ducks a 31-7 lead at the half.
The Beavers rebounded after the break with Collins running from 1-yard and 9-yards out for consecutive touchdowns.
After Freeman's 19-yard scoring run made it 38-21 for the Ducks, McMaryion's 6-yard scoring run closed the gap again for Oregon State and set up the final quarter.
''We played well at times, we played spectacularly at times, we played OK at times," Oregon coach Mark Helfrich said. "It was one of those games."