Eugene, OR (SportsNetwork.com) - Byron Marshall rushed for 133 yards and three touchdowns and No. 2 Oregon scored 28 unanswered points in the second half on Saturday to pull away for a 42-14 win over No. 12 UCLA.
UCLA scored two first-half touchdowns off an Oregon fumble and a blocked punt and recovered a fumbled snap deep in its own territory in the third quarter.
But the Bruins punted and the Ducks -- who had beaten their first seven opponents this season by an average of 40 points -- took a 21-14 lead on Marshall's 11-yard touchdown run.
The score opened the floodgates a little later than usual for Oregon (8-0, 5-0 Pac-12), which was held to its lowest point total of the season.
"We knew UCLA was good and they lived up to it," said Oregon coach Mark Helfrich. "They're a fantastic team, very well coached in every phase and it was just back and forth, a heavyweight fight.
"The second half was just a total team effort. Every single guy contributed to this."
Heisman Trophy candidate Marcus Mariota -- averaging 363 yards of total offense per game coming in -- threw for 230 yards with a touchdown pass to Bralon Addison and rushed for 18, falling well short of that number.
De'Anthony Thomas returned to rush for 31 yards and a touchdown after missing the last three games with an ankle injury and linebacker Rodney Hardrick ran 66 yards on a fake punt to set up Oregon's first touchdown.
Brett Hundley threw for just 64 yards with a touchdown pass to Thomas Duarte and also ran for 72 yards and a score for the Bruins (5-2, 2-2), who have lost two in a row after falling at Stanford last week. Paul Perkins rushed for 93 yards in the loss.
"It was a very disappointing loss. We didn't come up here to play them close," said UCLA coach Jim Mora. "We didn't come up here to give it the old college try. We came up here to win the game and we didn't get it done.
"We played hard but playing hard is not enough. We've got to get to the point where we play efficiently and where we don't make mistakes at critical times. ... We have to get to the point where we do things on a consistent basis that champions do and we're not there yet."
Oregon has won five in a row over UCLA by an average of 22.8 points.
But this one was a nail-biter for the Ducks, who were No. 3 behind Alabama and Florida State in the first BCS standings this week.
Their first-half miscues included a fumble on the game's second play and the blocked punt.
"The message at halftime was one play at a time," said Mariota. "That is kind of what we live by around here. The guys around me stepped up."
The game was tied 14-14 and the Ducks were at the UCLA 5-yard line when Mariota couldn't get to a low snap. The Bruins went three-and-out after the fumble and Marshall's 11-yard run to the left side gave Oregon a 21-14 lead.
"We started picking it up on offense and everything just started clicking," said Marshall.
Avery Patterson jumped in front of Shaquelle Evans to intercept Hundley, taking it back 33 yards to the UCLA 38 and setting up Mariota's 8-yard touchdown pass to Addison.
Marshall's third rushing touchdown, a 3-yarder, and Thomas Tyner's 2-yard run capped the scoring.
Earlier, wide receiver Keanon Lowe fumbled on Oregon's second play and UCLA took a 7-0 lead on Hundley's 4-yard run just 3:02 into the game.
The Ducks almost lost another fumble in their own territory when Anthony Barr stripped Mariota on a sack but Oregon recovered, setting up Hardrick's run on the fake punt.
Hardrick took a direct snap and went through the middle of the line. He wasn't touched until Evans spun him out of bounds at the Bruins' 8-yard line. Thomas was down inside the 1-yard line after a 7-yard reception but scored on the next play to tie the game.
Marshall scored on a 40-yard touchdown run to the right side after UCLA turned the ball over on downs to give Oregon a 14-7 lead early in the second quarter.
After Boseko Lokombo intercepted Hundley, Myles Jack busted through the line to block an Oregon punt and Duarte's 11-yard touchdown catch tied the game for UCLA.
Oregon's Alejandro Maldonado missed a 37-yard field goal wide right before halftime.
After a bye week, Oregon plays at Stanford on Nov. 7 ... UCLA is home next week against Colorado ... The Bruins lead the all-time series 39-27-0 but their last win was 16-0 on Nov. 24, 2007 ... The Ducks' 45-24 win at Washington on Oct. 12 was the only other time they were held under 55 points this season ... UCLA was also 12th in the BCS standings this week.