CORVALLIS, Ore. -- In the midst of a long scoring drought, coach Andy Enfield had a simple message for the USC Trojans.
"We talked about toughness," Enfield said.
Obviously the Trojans took it to heart, because it sparked an 18-0 rally.
Elijah Stewart had 18 points and USC won its fourth straight with a 74-67 victory over Oregon State on Saturday night.
Jordan Usher added 14 points for USC (15-6, 6-2 Pac-12), who have won four straight in the series against the Beavers (11-8, 3-4).
With their victory over the Oregon Ducks on Thursday, the Trojans won both games in the state of Oregon for the first time since the 2008 season.
Tres Tinkle had 21 points and seven rebounds for the Beavers. Tinkle is the only player in the Pac-12 that has reached double figures in every game this season.
The Trojans fell behind in the second half by as many as eight points, but rallied with just over six minutes left when consecutive 3-pointers from Usher gave the Trojans a 58-54 lead. Jordan McLaughlin added a layup and a 3-point play before an 18-0 run was capped by free throws from Stewart to put USC up 65-54.
The Beavers closed within 69-63 on Stephen Thompson Jr.'s jumper with 1:48 left, but got no closer. Thompson finished with 16 points.
Asked about those two key 3-pointers from Usher, Enfield pointed out that the freshman was 4-for-4 from the perimeter.
"He'd tell you that, too," Enfield smiled.
Oregon State coach Wayne Tinkle said to give Usher credit: "He hit some good shots. We didn't defend it right, we weren't getting to the corner."
Tres Tinkle had 16 points on Thursday night and the Beavers snapped a two-game losing streak with a 69-63 victory over UCLA.
McLaughlin scored the Trojans' last eight points, including six consecutive free throws, to help hold off Oregon for a 75-70 victory earlier Thursday night.
The Trojans made six of their first seven shots and led the Beavers 14-7. Jonah Matthews' 3-pointer gave USC a 23-16 lead as the Beavers struggled to find momentum. Each time Oregon State looked like it was mounting a rally, the Trojans responded.
But the Beavers pulled closer at the end of the half when Nick Rakocevic was called for a personal foul and Enfield got a technical. Tres Tinkle made both shots, then added two free throws to tie it at 33.
McLaughlin had a pair of free throws for the Trojans go into halftime up 35-33. Tinkle led all scorers with 14 points.
Thompson hit a 3-pointer to give the Beavers the lead at the start of the second half. Tinkle's layup extended the lead to 41-37, then his dunk pushed it to 45-37 and the momentum had fully shifted to Oregon State. USC didn't score for a span of 7:28.
The Trojans stayed close, and Usher's 3-pointer with 6:16 to go gave the Trojans back the lead.
"We had them where we wanted them, and then all of our momentum was taken away. The game was totally changed," Wayne Tinkle said.
The Beavers went into the game holding opponents to 68.4 points a game to lead the Pac-12.
USC has been winning even though the program has seen some upheaval. Just nine days ago the Trojans announced that sophomore guard De'Anthony Melton would not play for the team this season.
Melton, a sophomore guard who averaged 8.3 points, 4.7 rebounds and 3.5 assists last season, had not suited up in any games as the school investigated what it initially referred to as "a potential issue regarding eligibility."
Melton was one player mentioned in the FBI probe into college basketball, which revealed a pay-for-play scandal where schools would funnel money through shoe companies to a player in exchange for their commitment.
USC left open the possibility of Melton rejoining the team in the future.
USC: Juniors Bennie Boatwright and Metu went into the game as the second-highest scoring frontcourt in the Power 5. Metu was averaging 16.8 points per game while Boatwright averaged 15.6.
Oregon State: Tinkle has missed just one free throw over eight game games (38-for-39). ... The Beavers lost 62-53 to then-No. 17 Arizona before a second loss to then-No. 11 Arizona State last week.
TAKING CARE OF THE BALL: USC had just eight turnovers, compared to Oregon State's 14. The Trojans went into the game with the top assist to turnover ratio in the Pac-12. Nationally, USC ranked 16th with a 1.44 assist-to-turnover ratio going into this week's games. Overall USC was averaging 11.4 turnovers going into Saturday's game, best in the conference.
USC hosts Stanford on Thursday night
Oregon State plays at rival Oregon on Jan. 27
Mannion, who recently reclassified and is ESPN's No.11 overall player in the class of 2019, chose Arizona over Marquette.
He'll fit in with Sean Miller's plans for a faster tempo on offense.
The cream of the crop of American high school basketball will congregate in Colorado Springs from Oct. 5-7, as USA Basketball unveils its newly expanded Junior National Team minicamp in collaboration with the NBA, NCAA and NBPA.