EUGENE, Ore. (AP) -- Kenjon Barner set an example when the Ducks got lethargic.
The senior running back took over and scored late in the fourth quarter to cement No. 4 Oregon's 42-25 victory over persistent Fresno State on Saturday.
Barner ran for a career-best 201 yards, and scored three touchdowns. But he made his statement with his final TD, running the ball nine times before a 16-yard dash into the end zone with 3:51 left in the game. It was Oregon's only touchdown of the second half.
''You've got to keep moving and keep grinding,'' he said. ''You've got to adjust to the mistakes that you make.''
The Ducks (2-0) sprinted to a 35-6 first-half lead before the Bulldogs were able to slow them down in the second half.
''We knocked them off schedule when they tried to go fast in the second half. They tried to go fast again, and we knocked them off schedule again,'' said Fresno State defensive coordinator Nick Toth.
De'Anthony Thomas ran for 102 yards and two additional scores for the Ducks, while redshirt freshman quarterback Marcus Mariota completed 19 of 27 passes for 166 yards and a touchdown.
Derek Carr, the younger brother of former Bulldogs QB David Carr, completed 29 of 47 passes for 234 yards and a touchdown for Fresno State (1-1), a new member of the Mountain West Conference this season. Quentin Breshears kicked four field goals, including one from 43 yards.
The Ducks were coming off a 57-34 victory over Arkansas State in their opener last weekend, while the Bulldogs opened with a 37-10 win over Weber State in new coach Tim DeRuyter's debut.
DeRuyter, who took over when longtime coach Pat Hill was dismissed, has brought in a new spread offense he's dubbed ''fast, physical, fanatical'' while he and Toth have transformed Fresno State's 4-3 defense from last season into an attacking 3-4.
But in the end the Bulldogs were outmatched by the Ducks.
Fresno State went ahead first on Breshears' 39-years field goal but the lead was short-lived and Thomas scored on his first touch of the game, taking a pitch from Mariota and running 39 yards to make it 7-3.
Thomas appeared to score again on Oregon's next series on a 2-yard run, but the touchdown was nullified when the officials went back and reviewed the previous play, determining that Mariota had gone out of bounds at the 3-yeard-line and not the 2. Barner ran the 3-yards remaining for the score on the next play.
Oregon was hurt in the first half when starting receiver Josh Huff went down on a kickoff return. Huff appeared to hurt his left knee and had to be helped off the field. While he later walked unaided to the locker room, he came out on crutches in the second half.
After the game, Huff shrugged off the injury and said he'd be back at practice on Monday.
Guard Carson York, who tore his right patellar tendon in Oregon's Rose Bowl victory over Wisconsin last season, was also hurt during the game, but the extent of his injury was not available.
And Oregon was without senior free safety John Boyett, who did not dress for the game but was shagging balls during warmups. Oregon does not discuss injuries so it is uncertain if he was hurt.
Mariota found tight end Colt Lyerla with a 22-yard scoring pass early in the second quarter, and Thomas darted 51 yards, breaking several tackles, for another touchdown to make it 28-3.
Barner added a 3-yard scoring run before Breshears hit a 43-yard field goal to make it 35-6 at halftime.
Fresno State narrowed it to 35-16 in the third quarter when Carr found Isaiah Burse with an 18-yard touchdown pass and Breshears kicked a 25-yard field goal. Breshears added a 37-yard field goal in the fourth quarter to make it 35-19.
''Fresno State did a great job adjusting and we kind of came out like we had the game in hand,'' Barner said. ''We didn't have that intensity.
So Barner took it upon himself to rekindle it late in the fourth quarter, when he ran for 66 yards on 10 carries for Oregon's final scoring drive.
''He really took over on that last drive and put the game out of reach,'' Mariota said.
Barner takes over as Oregon's starting running back now that former Heisman finalist LaMichael James has moved on to the NFL's San Francisco 49ers.
Bulldogs' senior tailback Robbie Rouse capped the game with a 2-yard scoring dash for the final margin. Rouse ran for 115 yards on 27 carries. With 665 career carries, he has surpassed Michael Pittman (1993-97) for most in school history.
In his college debut last weekend against Arkansas State, Mariota threw for 200 yards and three touchdowns. On the practice squad last season, Mariota takes over for Darron Thomas, who threw for a school-record 33 touchdowns last season before leaving school with a year of eligibility left.
This Saturday didn't go as smoothly for Mariota, but that's what these early season games are for, offensive coordinator Mark Helfrich said.
''That's the part of it these guys have to learn,'' he said.
Fresno State has not defeated the Ducks since a 10-4 victory at Autzen Stadium in 1982. Oregon is 7-2 all-time against the Bulldogs.