Oregon beat No. 9 Washington 64-59 on Thursday night for its 13th straight victory over the Cougars.
"Our locker room is on fire down there and maybe this is the win we need to kind of energize us coming down the stretch," said Oregon coach Ernie Kent, whose team hasn't lost at home to Washington State since 1995.
With the victory, Oregon has now has defeated UCLA (No. 1), Arizona (No. 10) and Washington State this season, making the Ducks the only team in the country to defeat three top-10 teams.
"This is a top-10 team. We had to show the committee we're a tournament team," said Ducks freshman Tajuan Porter, who scored 21 points.
The Ducks (21-7, 9-7 Pac-10) had lost three consecutive games.
Washington State (22-5, 11-4) had won five straight since a 77-74 overtime loss to Oregon in Pullman.
In other Top 25 games, it was: No. 4 UCLA 85, California 75; No. 7 Memphis 99, Rice 63; No. 11 Nevada 84, Idaho 68; Loyola of Chicago 75, No. 15 Butler 71; and No. 18 Duke 71, Clemson 66.
After trailing by as many as 14 points in the first half, Oregon went up 46-43 midway through the second on Bryce Taylor's 3-pointer.
Washington State responded with a 9-0 run, and went ahead 52-46 on Daven Harmeling's 3-pointer.
Oregon closed to 55-53 on Porter's 3-pointer, then went ahead on another 3 by Porter with 3:36 left. Harmeling quickly put the Cougars back up with a dunk.
After Porter made a pair of free throws, Maarty Luenen's tip-in with under a minute left made it 60-57 for Oregon. After Taylor Rochestie scored for Washington State, Aaron Brooks' key layup put the Ducks up 62-59 with 12.9 seconds left.
Chamberlain Oguchi made a pair of free throws for Oregon for the final margin.
"It wouldn't have been like that if Tajuan hadn't stepped up and hit those big shots," Brooks said of his key layup.
No. 4 UCLA 85, California 75
At Los Angeles, Josh Shipp scored 22 points and Lorenzo Mata added 14 to lead a second-half comeback in UCLA's victory over California that extended the Bruins' home winning streak to 19 games.
UCLA (24-3, 13-2 Pac-10) completed a season sweep of the Golden Bears (14-13, 6-9), who had won their two previous games at Pauley Pavilion and dominated the first half.
Freshman Ryan Anderson led the Bears with 21 points and Omar Wilkes was among three players with 10 each.
No. 7 Memphis 99, Rice 63
At Memphis, Tenn., Willie Kemp scored 20 points to help Memphis beat Rice and clinch its second straight Conference USA title.
The victory extended Memphis' winning streak to 16 straight, longest in the nation. Memphis also has won 28 in a row at home.
Morris Almond led Rice with 15 points _ 12 points below his average.
No. 11 Nevada 84, Idaho 68
At Moscow, Idaho, Nick Fazekas scored 21 points and grabbed 14 rebounds to help Nevada beat Idaho.
Ramon Sessions added 15 points and Marcelus Kemp 14 points as Nevada (25-2, 12-1 Western Athletic Conference) won its eighth game in a row and 18th of the last 19. The Wolf Pack have the best winning percentage in the nation.
Idaho (3-24, 1-13 WAC) lost its 10th straight, continuing one of the worst seasons in team history. Keoni Watson led the Vandals with 27 points.
Loyola of Chicago 75, No. 15 Butler 71
At Indianapolis, Blake Schilb scored 28 points, Tracy Robinson hit five free throws in the final 36 seconds and Loyola of Chicago held off Butler for its first victory over a ranked opponent in 21 years.
It also gave the streaking Ramblers (20-9, 10-5 Horizon League) their seventh straight win, the longest streak since 1992, and assured league-leader Wrigh State the top seed in the conference tournament next week. Butler (24-5, 12-3) can still tie Wright State for the regular-season title with a victory over Detroit on Saturday but would get the second seed because of a tie-breaker.
No. 18 Duke 71, Clemson 66
At Clemson, S.C., Jon Scheyer scored 18 points to help Duke win its 21st straight over Clemson _ without any late help with the game clock.
When these teams met last month at Cameron Indoor Stadium, the Blue Devils' 68-66 victory was helped when officials incorrectly added time at the end _ the extra seconds more than enough for David McClure's winning layup.
This time, Duke (21-7, 8-6 Atlantic Coast Conference) opened a 21-point halftime lead and hung on as Clemson (19-8, 5-8) came within 69-64 in the final minute.
Scheyer, though, hit two foul shots with 5.7 seconds left to put the game away.
Cliff Hammonds and Vernon Hamilton had 14 points each for Clemson, which has lost eight of 10 since starting 17-0.