CORVALLIS, Ore. (AP) — Michael Penix Jr. threw for two touchdowns and ran for another, and No. 5 Washington remained undefeated and clinched a spot in the Pac-12 championship game with a 22-20 victory over No. 10 Oregon State on Saturday.

Played in a nearly constant rain, it was the final Pac-12 game at Reser Stadium as the conference currently stands. The Pac-12 collapsed over the summer, leaving Oregon State and Washington State as the lone remaining teams.

Rome Odunze caught seven passes for 106 yards and two touchdowns for the Huskies (11-0, 8-0, No. 5 CFP), who have won 18 consecutive games. Washington is departing for the Big Ten next season, along with Oregon, USC and UCLA.

Penix completed 13 of 28 passes for 162 yards. He has thrown for 30 touchdowns this season.

Damien Martinez ran for 123 yards and two touchdowns for the No. 10 Beavers (8-3, 5-3, No. 11 CFP), who were effectively eliminated from a shot at the conference championship. The loss ended a nine-game winning streak for Oregon State at Reser.

The Beavers closed to within 22-20 on Atticus Sappington's 35-yard field goal with 10:40 left in the game. Washington was forced to punt on the next series, and Oregon State fell short when DJ Uiagalelei's fourth-and-5 pass to Jack Velling at midfield was incomplete.

The win kept Washington alone atop league standings in front of No. 6 Oregon, which also has national championship aspirations and defeated Arizona State 49-13 earlier on Saturday. The Ducks have just one loss — to Washington earlier this season. The Beavers visit Oregon on Friday in Eugene.

On Washington's first series of the game, Penix hit Odunze with a 12-yard touchdown pass in a steady downpour at Reser. The Beavers answered with Damien Martinez's 3-yard TD scamper.

The Huskies went up 9-2 on a safety when Oregon State misplayed a punt with a bad snap that went over the head of the punter.

The wet and slippery conditions caused problems for both teams. Washington's Dillon Johnson gained of 42 yards to get to the Oregon State 9-yard line, but fumbled and the Beavers recovered. Then Anthony Gould fumbled a pass from DJ Uiagalelei and Washington recovered on the Oregon State 19. The Huskies, aided by a pass interference call, went on to score on Penix's 5-yard keeper.

Penix danced on the sidelines in celebration.

Oregon State closed the gap with Sappington's 38-yard field goal, but Washington capped the first half with Penix's 38-yard scoring pass to Odunze to lead 22-10.

A 39-yard field goal attempt by Washington's Grady Gross went wide left early in the third quarter.

Martinez scored on a 5-yard dash with 1:29 left in the third quarter to close the gap to 22-17. The 16-play drive took 9:56 off the clock and shifted momentum to the Beavers.

Uiagalelei gained 26 yards on a fourth-and-1 keeper to keep an Oregon State drive alive early in the final quarter. Martinez extended the drive, taking a short pass from Uiagalelei and stretching it for 19 yards, but the Beavers ultimately settled for Sappington's 35-yarder.

MOUNTAIN WEST ALLIANCE?

This week two people with knowledge of the situation told The Associated Press that the Beavers and the Cougars were moving toward keeping the Pac-12 alive as a two-team conference for the time being while striking a deal with the Mountain West to fill out their schedules. That could possibly lead to a longer-term deal between the schools and the Mountain West.

Earlier in the week a judge in ruled that Oregon State and Washington State, as the sole remaining members of the Pac-12, have sole control of the conference's assets. But the departing schools appealed to the Washington Supreme Court and won a temporary stay. Oregon State and Washington State have until Nov. 28 to respond.