Klay Thompson scored 26 points to help Washington State sweep the season series with cross-state rival Washington in an 80-69 win on Sunday night.

DeAngelo Casto chipped in 20 points and 13 rebounds for Washington State (18-10, 8-8 Pac-10), which snapped a two-game losing streak.

Isaiah Thomas scored 21 points to lead the Huskies (19-9, 10-6 Pac-10), who shot just 34 percent from the field in the loss.

Washington State jumped out to an early lead after holding Washington scoreless for more than seven minutes of the first half. The Huskies came into the game boasting the nation’s No. 2 scoring offense, but trailed by seven at halftime and by 21 points with 10:47 left in the second half.

But Washington clawed back, using a 16-4 run, keyed by 3-pointers on three consecutive possessions, to close the deficit to 65-59 with 4:04 left in the game. That would be as close as the Huskies would come as the Cougars shot 32 of 36 from the free-throw line in helping ice the win.