DeAngelo Casto scored 19 points and blocked three shots as Washington State beat Arizona 78-60 on Saturday, knocking the Wildcats out of a tie for first place in the Pac-10.
Klay Thompson had 14 points and Reggie Moore 12 points for the Cougars (15-8, 5-6), who had lost three straight. Washington State held Arizona to 42 percent shooting to sweep the season series.
Derrick Williams scored 16 points for Arizona (12-11, 6-5), which was coming off a narrow loss at Washington that ended a four-game winning streak. The Wildcats were tied for first with three other teams heading into Saturday's games.
It was Arizona's first game since the university announced Friday that it had placed its men's basketball program on probation for the 2010-11 and 2011-12 seasons for violations by Hall of Fame coach Lute Olson related to an offseason AAU tournament in 2008.
