EUGENE —

Oregon State was the better football team for much of the 2009 Civil War. In the end, however, Oregon was more resilient.

The Ducks trailed four times — and by as many as nine points in the third quarter — but rallied to beat the rival Beavers at chilly but charged-up Autzen Stadium. Thursday night’s tense 37-33 decision sends Oregon to its first Rose Bowl since 1995.

Ohio State awaits the 10-2 Ducks in Pasadena on New Year’s Day.

“This is unbelievable,” said star freshman UO running back LaMichael James, reflecting after his 166-yard, three-touchdown rushing performance. “I feel like I’m dreaming right now.”

What awaits the 8-4 Beavers, sadly, is a bid to a far lesser bowl game. (The best bet appears to be the Maaco Bowl, Dec. 22 in Las Vegas.) Oregon State was gunning for its first Rose Bowl berth since the 1964 season and seemed to have it in its grip, only to be denied by the Ducks — painfully, for the second year in a row.

It was billed as the biggest Civil War game ever played in a rivalry dating back to 1894. To the winner would go the Pac-10 Conference championship and the coveted invitation to play in the “granddaddy” of all bowl games, the Rose Bowl.

The Beavers didn’t exactly give the game away. They never fumbled, and their quarterback, Sean Canfield, passed 36 times without an interception. The worst that could be said of OSU’s execution is that the Beavers were flagged for no fewer than five false-start penalties, no doubt at least partially attributable to the noise generated by an Autzen-record crowd of 59,597.

Twice, though, those penalties contributed to the stalling of drives in Oregon territory. Justin Kahut capped both of those drives with field goals, part of a four-for-four performance by the junior kicker from Portland.

But the Beavers had to know they were not going to beat the high-scoring Ducks with field goals.

They needed touchdowns. And the two they got on possessions sandwiching halftime — a 28-yard TD pass from Canfield to James Rodgers 14 seconds before the break, and a nine-yard scoring strike from Canfield to Casey Kjos to complete a 75-yard drive after the second-half kickoff — put Oregon State up 30-21.

With a two-possession lead, the Beavers could darn near smell the roses. But if the Ducks were daunted, they didn’t let it show.

“Remember the Arizona game?” asked UO senior safety T.J. Ward, referring to the Ducks’ comeback from a 24-14 fourth-quarter deficit to beat the Wildcats 44-41 in double overtime two weeks ago in Tucson.

“We’ve been in situations like that all season,” Ward continued. “But we find a way to win.”

Needing an answer to keep the Beavers from running away with the bouquet, Oregon responded with a game-turning drive that featured the return to action of LeGarrette Blount. The powerful senior tailback — a 1,000-yard rusher in 2008 — was suspended after punching a Boise State player in the aftermath of the Ducks’ season-opening loss and had not played in 10 1⁄2 games, but his impact Thursday night was almost immediate.

On Oregon’s first possession of the second half, Blount’s first carry in exactly three months produced a modest two yards. But when his name was announced after the short gain, the home crowd cheered loudly.

The cheers became a roar seven plays later, when Blount broke free over the left side and dived over the goal line for a 12-yard touchdown with 5:45 remaining in the third quarter.

“I was so happy for LeGarrette,” said James. “He’s been working so hard … I love LeGarrette like a brother.”

But even after Bend’s Morgan Flint kicked the extra point to cut the Beavers’ lead to 30-28, the Ducks had work to do.

On the next OSU possession, Canfield engineered yet another scoring drive. The march got to the Oregon 23-yard line before yet another false-start penalty pushed back the Beavers, who settled for a 45-yard Kahut field goal and a 33-28 lead.

The Ducks overtook the Beavers just three plays after the ensuing kickoff, when James found room to the left and bolted up the left sideline for 52 yards and a touchdown.

Oregon failed on a two-point conversion try, but the Ducks had once again regained the lead, up 34-33.

It would be the last of the game’s five lead changes.

Oregon State punted on the first play of the fourth quarter, and the Duck offense was soon back on the move. A 24-yard pass-and-run from quarterback Jeremiah Masoli to wideout Jeff Maehl helped set up a 29-yard field-goal try by Flint.

As he had been on 14 of his previous 16 attempts this season, the former Lava Bear was true with his kick. But as the ball sailed through the uprights, the referee was waving the play off. He then penalized Oregon five yards for delay of game.

The Ducks’ lead remained at a single point, and Flint would have to try again — this time from 34 yards.

“I don’t like to be on the field too long,” Flint said after the game. “I like to kick and get back off. But I had to adjust to the situation.”

He did, then calmly booted his 11th consecutive successful field goal for what proved to be the final points of the game and a 37-33 UO lead with 10:13 left to play.

While there was no more scoring, plenty of intrigue remained.

The Beavers, on the strength of another big play by Canfield — a 31-yard completion to Rodgers, the longest of his 10 receptions in the game — were quickly back in business with a first down at the Oregon 22.

But a short pass from Canfield to Jacquizz Rodgers was good for only a yard. Then the Duck defense came up with one of its biggest plays of the night, as linebacker Kenny Rowe sacked Canfield for a six-yard loss.

On fourth and 15 from the UO 27, Oregon State coach Mike Riley had a decision to make. A field-goal try would have come from 44 yards — well within Kahut’s range. But that would have left the Beavers a point short, at 37-36, and OSU would run the risk of the Ducks keeping the ball for the remaining six-plus minutes.

After calling a timeout to ponder his options, Riley rolled the dice and played to his strengths: Canfield passing to James Rodgers. The play developed as planned, but for one of the few times all night Canfield missed his mark, throwing low to Rodgers right at the first-down marker on the left sideline.

The incompletion gave Oregon the ball with 6:09 to play. The Beavers had two timeouts left. The Ducks, known more for their quick-strike attacks than for long, time-consuming drives, needed to either score or find a way to milk the last six minutes off the game clock.

With 3:29 remaining, Oregon faced a fourth-and-three situation at the OSU 33. After a timeout to decide whether to try a 50-yard field goal, punt, or go for it, Ducks coach Chip Kelly kept his offense on the field for what might have been the play of the game.

“We decided to go for it,” said Masoli. “We wanted to keep the ball in our hands and get the game over with.”

Masoli, who at a stout 5 feet 11 and 220 pounds resembles a linebacker in quarterback pads, scrambled to his right. He raced toward the sideline, but between him and the first-down marker stood Beaver safety Lance Mitchell.

“I’ve gotta get the first down,” Masoli said later, recalling his thoughts as he headed for a collision with Mitchell.

The impact bowled Mitchell over, and Masoli twisted ahead for a six-yard gain and a crucial first down.

Afterward, Kelly sang the praises of his never-say-die quarterback.

“I think Jeremiah, for what we do,” said the first-year Oregon head coach, “is the best quarterback in the country.”

But Oregon State proved just as relentless as the Ducks. On first down, Blount was taken down by linebacker Dwight Roberson for a six-yard loss. And after OSU used another timeout to conserve time, the Ducks faced another fourth down — this time with 1:43 to play and a short two yards to go from the Beaver 19.

Kick a field goal for a four-point lead? And give the dangerous Canfield a chance to come back for a winning touchdown?

Nope, Kelly decided. And Flint said he was fine with the call to go for it.

“You want to be the guy to go out there and kick it in that situation,” Flint said. “But another first down, and that’s the game.”

Kelly ordered up an option play that the Beavers strung to the left side before Masoli pitched the ball to Kenjon Barner, whose five-yard gain earned a first down and sealed the victory for the Ducks.

“My hat’s off to Oregon State,” said Kelly, calling the Beavers’ Rodgers brothers “two tremendous football players.”

“And Canfield,” the coach added, “he’s the real deal.”

In a packed media room after the game, Kelly and Mike Bellotti, the former UO coach and current athletic director, accepted the Pac-10 Conference championship trophy.

Then Jeffrey Throop, acting president of the Tournament of Roses, offered the Ducks a formal invitation to play Jan. 1 in the Rose Bowl.

It’s the kind of invitation for which no R.S.V.P. is required. Yet Kelly, clearly enjoying the moment, offered a deadpan reply:

“We’ll go.”

The Ducks had better go. With a hard-fought victory in perhaps the greatest of 113 Civil Wars, they’ve earned it.