The time for leadership from the two seniors was now.
Cook responded by matching his career high with 26 points and Benjamin had his best scoring game since early December with 16 off the bench to lead Oregon to an 89-81 victory over No. 21 Southern California on Thursday night.
''I told (Elgin) and Dwayne that they played the way seniors are supposed to play, so I shouldn't be shocked,'' Altman said. ''I was disappointed in them and I expressed that to them after the Colorado game. I think they took it as a challenge.''
Chris Boucher added 16 points and nine rebounds for the Ducks (15-4, 4-2), who moved into a tie for second place in the Pac-12 with their 18th consecutive home win. Oregon 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.
Boucher led the Ducks to a 43-38 edge in rebounds.
''We outrebounded them and I thought that was a big stat going into tonight's game,'' Altman said. ''The second half we had only three turnovers. I thought that was big.''
Freshman Bennie Boatright had 23 points and 12 rebounds, both season highs, to lead USC (15-4, 4-2) 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 in losing for the 11th consecutive time to Oregon.
''"When another team goes on a run, you have to score with them,'' USC coach Andy 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.''
Benjamin's two steals in Oregon's press helped key the run and, even though he didn't have a rebound for a second straight game, the sixth man's defensive presence more than made up for it.
''Those two big steals he got in the press really changed the momentum of the game,'' Altman said.
Benjamin's 16 points, which included three of Oregon's eight 3-pointers, were the most he's scored in a dozen games.
''I just play the same way,'' Benjamin said. ''My confidence is always there. I knew it would come one game, and tonight was the night.''
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.
Altman was concerned that USC was coming off an eight-day break before Thursday night's game. Now comes UCLA, which has had an extra day of rest before Saturday afternoon's visit. ''This is where the schedule makers didn't do us much good, so we're just going to have to fight through it,'' Altman said. ''We have to be ready at 1 o'clock on Saturday and it's going to come very quickly.''
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.
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.