EUGENE, Ore. -- On a night when No. 3, No. 4, and No. 5 were defeated, No. 2 Oregon had no trouble avoiding an upset.
The Ducks jumped on No. 23 Washington from the start, taking a 21-0 lead after the first quarter and stretching it to 35-7 by halftime before finishing off a 52-21 win Saturday night at Autzen Stadium.
While Florida State, LSU and Georgia all dropped off the list of unbeatens earlier in the day, Oregon improved to 6-0 and cemented itself at No. 2 behind Alabama in the polls midway through the regular season.
"I am very proud of how we came out and how we finished," Oregon coach Chip Kelly said. "We knew we would get Washington's best shot, so we had to make sure we do what we do, and we executed well."
The Ducks piled up 319 yards of offense in the first half to pull away from the Huskies. Freshman quarterback Marcus Mariota threw three touchdown passes in the first half.
Mariota completed 15 of 24 passes for 198 yards and four touchdowns. He ran seven times for 40 yards and helped Oregon finish with 497 total yards of offense.
"Marcus has shown improvement, and that is one of the awesome things about him," Kelly said. "He rarely makes the same mistake twice. He is always trying to improve and asking questions. He wants to get better, and the way he played tonight is no surprise to us."
Kenjon Barner contributed 122 yards on 20 carries for the Ducks.
Oregon scored first after Washington's Marvin Hall fumbled a punt, giving the Ducks the ball at the Huskies' 20-yard line. Two plays later, Oregon's De'Anthony Thomas scored on a 16-yard run to put Oregon ahead 7-0 midway through the first quarter.
Oregon put together a longer drive for its second score of the first quarter, going 80 yards on four plays in just 1 minute, 3 seconds. Mariota threw a 48-yard pass to Colt Lyerla, then found Keanon Lowe for a 21-yard touchdown on the next play.
On Washington's next possession, Avery Patterson intercepted a pass and returned it 43 yards for a touchdown to put the Ducks ahead 21-0. It was the second straight week Patterson returned an interception for a score.
"It was an out route, and I just broke on the ball and happened to be in the right place," Patterson said. "I saw him run the out route and immediately jumped the route. I broke on it and went to the house. Once you get that first one, you want to keep getting them. It's addictive."
Washington (3-2, 1-1 Pac-12) cut the lead to 21-7 early in the second quarter when Bishop Sankey scored on a 1-yard touchdown run.
Oregon (6-0, 3-0 Pac-12) answered right away when Mariota threw a 10-yard touchdown pass to Lyerla. The Ducks stretched the lead to 35-7 midway through the second quarter when Mariota completed a 34-yard TD pass to Josh Huff.
Oregon added on in the third quarter when Rob Beard booted a 28-yard field goal to put the Ducks ahead 38-7.
Sankey answered with a 6-yard touchdown run to get the Huskies within 38-14 with 2:56 left in the third.
Mariota responded with his fourth touchdown pass of the game, a 14-yarder to Lyerla to push the lead back to 45-14 on the first play of the fourth quarter. Oregon freshman Byron Marshall added a 4-yard touchdown run to increase the lead to 52-14.
Sankey gained 104 yards on 25 carries to lead the Washington offense. Huskies quarterback Keith Price completed 19 of 31 passes for 145 yards. He was intercepted twice.
"We really felt like we could come in and play with them," Washington coach Steve Sarkisian said. "I don't think the final score is indicative of their football team as compared to ours, and that part is really frustrating to me."
NOTES: Oregon linebacker Michael Clay, who was injured last week against Washington State, did not play against the Huskies. ... Lowe originally committed to play at Washington before signing with Oregon out of Portland's Jesuit High School. ... Oregon has returned four interceptions for touchdowns in its last three games. The last time the Ducks returned four interceptions for touchdowns in a season was 1991.