CORVALLIS, Ore. (AP) -- In the pouring rain, Alexis Serna hit his 40-yard field goal and began leaping all over the field in victory, pumping his fists.
Serna has made some tough, pressure-packed kicks before, and he was last season's Lou Groza Award winner for the nation's best kicker.
But this was the Civil War.
Less than a minute later, Oregon State's defense came through and blocked a potential game-winning field goal by the Ducks. The Beavers won the 110th edition of the Civil War 30-28.
"We're certainly proud of our kicker. I can't say enough about him," Oregon State coach Mike Riley said. "He's a part of our great story through the years."
Oregon's Matt Evensen, put in after kicker Paul Martinez was ineffective, attempted a 44-yard field goal with 20 seconds left, but Ben Siegert knocked it down and the home team won this in-state rivalry for the 10th straight season.
"That's a difficult one to swallow in that we came back and gave ourselves an opportunity to win and our kicking game let us down," Oregon coach Mike Bellotti said.
Dixon did not play.
Leaf led a fourth-quarter drive, capped by a 26-yard scoring pass to Jordan Kent and a QB keeper for a 2-point conversion, that put the Ducks (7-5, 4-5 Pac-10) ahead for the first time in the game, 28-27.
Oregon State (8-4, 5-3) took the ball down to the Ducks' 22 and settled for Serna's rain-soaked 40-yarder in a driving rain. It proved to be enough.
"I just hit it and I was hoping it snuck through the left upright, and it did," Serna said.
Matt Moore completed 16 of 22 passes for 255 yards and one touchdown for the Beavers, who have won six of their last seven games.
Serna made field goals from 49, 50 and 40 yards.
Leaf completed 25 of 42 passes for 274 yards and a score. He was intercepted once.
The game went sour for Oregon on its very first series. Dante Rosario's fumble was recovered by Oregon State's Brandon Hughes and the Beavers went on to score on Moore's 11-yard pass to Jason Vandiver.
Oregon tied it at 7 on Jonathan Stewart's 2-yard scoring dive with 2:19 to go in the first quarter.
Oregon State pulled back ahead with Serna's 39-yard field goal.
Leaf was intercepted by Oregon State's Derrick Doggett, who returned it 34 yards for a touchdown to put the Beavers up 17-7.
Serna just barely cleared a 50-yarder to make it 20-7.
Oregon narrowed it on Stewart's 22-yard scoring run to open the second half, but his Oregon State counterpart, Yvenson Bernard, answered with a 6-yard TD rush.
Stewart rushed for a 2-yard touchdown midway through the fourth quarter that made it 27-20. The extra point was blocked. Then Leaf found Kent in the end zone and got the two himself for an Oregon lead with 3:07 to go.
"People can say we give up or quit, but that's never been the circumstance," Leaf said. "You watch the fourth quarter of this game and you know every kid was giving it everything they had, and you have to respect that."
Nearly constant rain made the field slippery, and there were a few stumbles and dropped balls on both sides.
Moore called Serna a "stud."
"We knew if we got down there he would put it through for us and he did," Moore said. "He was clutch all day."
Evensen had made one prior field goal this season. When asked about switching kickers for the possible game winner, Bellotti replied: "Well, Paul made one kick, one extra point and missed two field goals and an extra point. So yeah, I made the change and it was totally my decision."
On his block, Siegert said the ball snapped, and he put his head down and pushed. Something hit his helmet.
"I knew it had to be the ball," he said. "At that point, I knew it was over."
Oregon's last win at Reser Stadium was back in 1996, when the Ducks won 49-13. Oregon holds the overall lead in the series 55-45-10.
South Carolina football coach Will Muschamp joins The Paul Finebaum Show to explain what it's like working under Nick Saban.
With spring ball a month away, we'll be ranking the position groups in the Big 12 over the next two weeks, starting with the quarterbacks.
Former South Carolina head football coach Steve Spurrier joins The Paul Finebaum Show to discuss the state of SEC football.
On The Paul Finebaum Show, former South Carolina head football coach Steve Spurrier discusses his transition out of the Gamecocks' football program.
Terrel Hunt missed 18 games the last two seasons due to injury.
Former Oregon quarterback Morgan Mahalak has transferred to Towson and is expected to compete for the starting job next season.