LOS ANGELES (AP) -- Derrick Williams scored 22 points and No. 16 Arizona rode its 3-point shooting to a 78-69 victory over Oregon State in the Pac-10 tournament quarterfinals Thursday.
The top-seeded Wildcats (26-6) advanced to play fourth-seeded Southern California in Friday's semifinals at Staples Center.
Kevin Parrom added 13 points, helping the Wildcats end a three-year skid in the tourney quarterfinals. A year ago, they lost to UCLA and finished 16-15, ending the school's streak of 25 consecutive NCAA tournament appearances.
Now, Arizona remains on track to add its first league tourney title since 2002 to the regular-season championship it wrapped up last weekend. Hall of Fame coach Lute Olson, who began the school's NCAA tourney streak in 1985, was in the crowd.