CORVALLIS — Southern California's players posed a simple question to each other before their game Friday night against No. 9 Oregon State.

The answer came in the form of a statement-making victory.

Sadie Edwards scored 17 points, Courtney Jaco had 15 and USC upset Oregon State 70-50 on Friday night, snapping the Beavers' seven-game winning streak.

"Before the game, we talked amongst each other, and we said, 'Why not us? Why can't we be the team to come in here and win?'" Edwards said.

Sydney Wiese had 17 points to lead Oregon State (22-3, 11-2 Pac-12). With two assists, Wiese moved within one of Leilani Estavan's career record (577) for the Beavers.

The victory snapped a two-game skid for USC (13-11, 4-9). Kristen Simon added 14 points and seven rebounds for the Trojans.

Valerie Higgins' jumper gave USC a 52-40 lead with just more than five minutes left, and Oregon State could not catch up. The loss snapped a 15-game Pac-12 winning streak for the Beavers at Gill Coliseum.

"Our shots weren't falling and they were getting everything they wanted," Wiese said. "They really put us on our heels. They had that press on us, and we weren't handling it the way that we should, for whatever reason. Games like that happen. Give credit to USC. They came out and wanted to smack us and they did."

The Beavers will play No. 15 UCLA on Sunday. Oregon State's only previous conference loss this season came against the Bruins, 66-56 at Pauley Pavilion on Jan. 13.

Earlier on Friday night, Oregon defeated UCLA 84-75.

UCLA's 85-76 victory over No. 8 Stanford on Monday had given Oregon State sole possession of the top spot in the league standings heading into Friday night's game.

The Beavers, who claimed a share of the Pac-12 regular-season title last year before winning the conference tournament, play three of their last five remaining games at home. They'll host Stanford during the final weekend of the regular season.

The Trojans weren't daunted Friday.

"Our coach told us before the game that the key to this game is believing that you can be here, believing that you are supposed to be here, believing that you can win this game," Edwards said. "And we carried that into this game and we played hard on both ends. We made plays and everybody that came in contributed."

The Beavers jumped in front 9-2, but the Trojans responded with a 15-0 run capped by Edwards' 3-pointer. Wiese hit a 3 to end the Beavers' drought.

USC padded its lead heading into the second quarter, going up 27-14 before Oregon State came back with a 12-0 run. Wiese and Kat Tudor hit layups to pull the Beavers within one, but the Trojans went into the break with a 29-26 lead. Edwards led all scorers at halftime with 10 points.

The Trojans kept Oregon State from pulling in front after the Beavers tied the game at 31 early in the third quarter. Southern California pushed the lead to 45-38 late in the period on Minyon Moore's 3-pointer.