EUGENE — True freshman Nick Wilson scored three touchdowns and Arizona stunned heavily favored Oregon once again, holding off the second-ranked Ducks 31-24 on Thursday night.
Terris Jones-Grisby plowed into the end zone from a yard out for the tiebreaking touchdown with 2:54 left. Wilson ran for a pair of scores and caught another to lift the Wildcats (5-0, 2-0 Pac-12), who were 24-point underdogs.
It was the second straight season and third time since 2007 that an unranked Arizona team upset an Oregon squad ranked in the top 5.
Arizona has won its first five games for the first time since 1998.
The loss silenced Autzen Stadium's 100th straight sellout crowd and damaged the Ducks' chances of getting a spot in college football's first postseason playoff.
With his team trailing 24-14 going into the final quarter, Oregon's Matt Wogan made a 21-yard field goal. Marcus Mariota then hit Keanon Lowe with a 9-yard scoring pass to tie it with 8:21 left.
With Arizona driving downfield, the Ducks (4-1, 1-1) sacked Anu Solomon on third-and-8, but Tony Washington was called for unsportsmanlike conduct to give the Wildcats a first down.
A pass interference call got Arizona closer for Jones-Grisby's go-ahead touchdown.
On Oregon's ensuing series, Mariota was sacked by Scooby Wright, who stripped the ball from the Heisman Trophy hopeful and recovered it himself.
Arizona then gained a clinching first down on the ground and ran out the clock.
Mariota threw for 181 yards and a touchdown. He also caught a TD pass, but was sacked three times and turned the ball over for the first time all season.
It was the first time Oregon had lost to an unranked team at home since the 2007 Civil War when it was beaten by rival Oregon State 38-31 in overtime.
Last November, the No. 5 Ducks lost to Arizona 42-16 in Tucson, dashing any hopes the team had for a national championship.
Arizona's blowout win last year was the school's first over a top-5 team since knocking off No. 2 Oregon in 2007.