Tia Presley and Lia Galdeira each had 17 points on Friday night as Washington State beat No. 21 Colorado 70-60.
WSU (11-6, 5-0 Pac-12) improved to 3-1 against ranked opponents this season and continues its best start in conference play since opening 5-0 as a member of the Northwest Women's Basketball League in 1977-78.
The Cougars had a 60-50 lead on Dawnyelle Awa's 3-pointer with 6:18 to play before both teams went scoreless for two minutes.
Brittany Wilson's 3-pointer for Colorado ended the drought and sparked a 9-4 run that brought the Buffalos within 64-59 with 2:27 to play.
The Cougars stopped Colorado's next three possessions as Presley and Galdeira each had steals and WSU made 6 of 8 free throws in the final minute to close the game out.
Jen Reese led the Buffaloes (11-5, 1-4) with 15 points and Arielle Roberson chipped in 13.