EUGENE, Oregon — Being nationally ranked for the first time in seven seasons didn't serve No. 21 Southern California very well Thursday night.
What the Trojans found in Oregon was their mirror image, and their chance to keep pace with Washington atop the Pac-12 standings disappeared in the second half.
Elgin Cook matched his career high with 26 points and Chris Boucher had 16 points and nine rebounds to lead the Ducks to an 89-81 victory over USC, which lost for the 11th consecutive time to the Ducks.
""It was two athletic teams on the court," USC coach Andy Enfield said. "It was a fun basketball game. Unfortunately, it wasn't as much fun for us as it was for Oregon.
"They can score at every position like we can. They're a very high-scoring team. They just did a better job of getting in the lane and making plays."
Dwayne Benjamin also had 16 points off the bench for Oregon (15-4, 4-2), which moved into a tie for second place in the Pac-12 with its 18th consecutive home win. The Ducks held the Trojans (15-4, 4-2), the conference's best 3-point shooting team, to 8 of 28 (28.6 percent) from long range.
Freshman Bennie Boatright had 23 points and 12 rebounds, both season highs, to lead USC before fouling out late in the game. Julian Jacobs also had 18 points, six rebounds and five assists for the Trojans.
USC lost contact with the Ducks when they rode a 13-1 run to a 71-56 lead midway through the second half. The Trojans never got closer than seven the rest of the way.
"When another team goes on a run, you have to score with them," Enfield said. "We missed a wide-open dunk, we missed three wide-open jump shots and we turned the ball over twice.
"If you're going to do that, you're going to give the other team opportunities to score."
Jordan McLaughlin, who leads six Trojans averaging in double figures at 13.5 points per game, was held to three, matching his season low. USC came in shooting 41.1 percent on 3-pointers but had its poorest showing since the end of nonconference play.
""We missed a lot of open shots from the 3-point line, and we generally shoot a higher percentage," Enfield said "Two or three of those go in, and you're talking about a one-possession game. . That's basketball."
The lead changed hands five times in the first half before a 10-0 Oregon run, highlighted by Benjamin's two 3-pointers, put the Ducks up by nine on their way to a 46-41 lead at the break.
Oregon had three scorers in double figures by the half, led by Cook"s 12 points and 10 each from Boucher and Benjamin.
Meanwhile, USC had its poorest shooting first half in Pac-12 play, making 16 of 38 (42.1 percent), along with missing five of nine free throws.
USC had 78 dunks coming into the game and added several more against the Ducks, but the one that got away hurt when Oregon was pulling away in the second half. Nikola Jovanovic had his slam rejected by the rim when it snapped back after he grabbed it on his follow-through and led to a Duck fast break.
Two key steals by Dwayne Benjamin were key during the second-half run that Oregon used to build its lead to 15. However, the Trojans finished with just nine turnovers against the conference leader in steals. "We're not going to play perfect all season," Enfield said. "They missed some shots, and we had a couple of crucial turnovers, so it's not like we played poorly. They just played better than us."
USC: The Trojans, who start Pac-12 play with five of their first seven games on the road, are now 2-2 away from home in the conference. USC hasn't won in Eugene in seven years. . USC felt short of matching the best start by a Trojan team in 24 seasons. The 1991-92 squad started 17-3.
Oregon: The victory was the Ducks' second over a ranked team this season. Oregon beat then-No. 20 Baylor in mid-November. . Casey Benson, the national leader in assist-to-turnover ratio at 5.8 per game, had three assists and two turnovers in the win. . Oregon is now 87-13 after 100 games in five-year-old Matthew Knight Arena. USC was also the first opponent to lose there when it helped christen the building in 2011.
USC plays at Oregon State on Sunday.
Oregon hosts UCLA on Saturday.