EUGENE, Ore. >> No. 3 Oregon held the No. 22 Wildcats out of the end zone and former St. Louis prep star Marcus Mariota threw two touchdowns in a 49-0 victory on Saturday night. The defense helped with two touchdowns of its own off interceptions.

“The defense did an unbelievable job. To hold them to zero points says enough about what they did,” Oregon quarterback Mariota said.

It was the Ducks’ first shutout in conference play since a 35-0 victory over Stanford on Oct. 25, 2003.

The game was billed as an offensive juggernaut between the Pac-12’s two fastest and highest-scoring offenses, but Oregon’s D thwarted the Wildcats in the red zone six times and forced four Arizona turnovers.

“I’ll say we didn’t expect this,” Oregon safety Brian Jackson said. “But I’m not surprised it happened.”

Oregon came in averaging 54 points per game, while Arizona wasn’t far behind at a little more than 46 points. Much was made about the meeting between the speedy Ducks under Chip Kelly and Arizona’s spread offense under no-huddle, up-tempo pioneer Rich Rodriguez.

But the Ducks (4-0, 1-0) held just a 13-0 lead at the break before finally finding their stride in the second half. Arizona never found it.

“Offensively, it was a tale of four bad quarters. Disappointing we didn’t execute better, especially in the red zone. You can’t afford to do that against anybody, let alone Oregon,” Rodriguez said.

Mariota threw for 260 yards and two touchdowns, including a 55-yard scoring pass to freshman Bralon Addison. Ifo Ekpre-Olomu and Tory Hill each returned interceptions for scores.

Matt Scott passed for 210 yards for Arizona (3-1, 0-1) but was intercepted three times. Scott left the game for a few minutes in the first quarter and although he appeared to be fine when he sprinted back on the field, Rodriguez later revealed that Scott had hurt his hip.

Oregon held Arizona to 332 total yards in offense, well off the Wildcats’ average of 605 yards going into the game.

Things got off to a sloppy start Saturday as Oregon failed on fourth down and each team turned the ball over before Mariota found Daryle Hawkins with a 17-yard touchdown pass midway through the first quarter.

Arizona got as close as the 2-yard line on the next series, but couldn’t punch it in and turned the ball over on downs. The Wildcats’ struggles’ continued when John Bonano’s 31-yard field goal was blocked early in the second quarter.

Rob Beard hit a 27-yard field goal to increase Oregon’s advantage to 10-0. It was the Ducks’ first FG of the season. Beard added a 41-yarder late in the first half to make it 13-0 at the break.

Oregon’s hybrid 3-4 defense under longtime coordinator Nick Aliotti held the Wildcats to 141 yards in total offense in the first 30 minutes. Meanwhile, Arizona’s new 3-3-5 defense kept the normally prolific Ducks from piling on points.

There was more of the same to open the second half, and the first two possessions by both teams ended in punts.

But then the Ducks started rolling. De’Anthony Thomas returned Arizona’s third-straight punt 38 yards, setting up a 35-yard pass to Colt Lyerla, who finished it off with a 1-yard touchdown run. The drive took just three plays and 29 seconds.

Kiko Alonso intercepted Scott, leading to Mariota’s long TD pass to Addison, before Ekpre-Olomu ran his interception back 54 yards to make it 35-0.

Bryan Bennett added an 8-yard scoring run with 4:02 left in the game and Hill intercepted Scott’s backup, B.J. Denker, for a 29-yeard touchdown and the final margin.