SEATTLE -- Washington coach Lorenzo Romar has seen this before from C.J. Wilcox. One 3-pointer starts to drop, then another and suddenly Wilcox is hitting everything.

Washington's sharpshooting guard put on another display Sunday that ended the Huskies' lengthy losing streak against ranked opponents.

"When he gets in a zone he's pretty special that way," Romar said.

Wilcox set career highs with seven 3-pointers and 31 points, including 21 in the second half, and Washington ran away from No. 15 Colorado for a 71-54 victory. Wilcox topped his previous high of 30 points set earlier this season against Boston College.

But the surprising part wasn't Wilcox getting hot or the improving Huskies knocking off a ranked opponent playing short-handed after Colorado star Spencer Dinwiddie went down with a knee injury in the first half.

The shock was the length in time since the Huskies had beaten a ranked opponent. It was Washington's first win over a ranked team since Isaiah Thomas' jumper beat then-No. 16 Arizona in the 2011 Pac-10 Conference tournament championship game.

Washington (11-6, 3-1 Pac-12) had lost 12 straight against ranked teams. The last time Washington beat a ranked team in the regular season was a home win over Texas A&M in December 2009.

Andrew Andrews added 14 points and Nigel Williams-Goss had 12 as the Huskies continued to improve.

"When you are rewarded with a win it continues to increase that attitude and that belief," Romar said.

Dinwiddie crumpled to the court after taking an awkward step on a fast break and his left knee buckled. He was on the court for a few minutes while trainers and coach Tad Boyle came on to his side. Dinwiddie was helped to his feet but had to be assisted off the court with his arms around teammates.

Dinwiddie, who had seven points in 15 minutes, was chastised by Boyle after scoring a disappointing six points in 38 minutes on Wednesday night. He left the arena with a large brace on his left knee and was expected to be examined on Monday in Boulder.

The Huskies outscored the Buffaloes 49-29 after Dinwiddie's injury.

"My gut is not good. But we'll see. If he's out, he's out," Boyle said. "I just feel so bad for the kid because he's worked so hard."

Josh Scott led Colorado (14-3, 3-1) with 15 points, but the Buffaloes' struggles went beyond not having Dinwiddie around in the second half.

Askia Booker, the reigning Pac-12 player of the week, was 0 for 9 from the field and went scoreless for just the second time in his college career. The last time Booker failed to score was late in his freshman season against Arizona.

"When Spencer went down he really tried to force things and he's not good when he forcing things," Boyle said of Booker. "We didn't show patience, we didn't show composure on the offensive end and that's how you turn it over 20 times."

The loss of Dinwiddie also impacted the Buffaloes defense. He was no longer available to chase Wilcox around and he took advantage of the clean looks.

"I know they were trying to key on me and having him not leaving me as much as he normally would," Wilcox said. "He's an athlete. It's tough to score on athletes. When he went down, we as a team, but me as well, just had to take advantage of that."

Washington started the second half on a 12-5 run thanks to three 3-pointers from Wilcox. The complexion of the second half could have changed when Perris Blackwell, the Huskies' only true inside presence, picked up his fourth foul with 15:52 remaining.

Scott tried to stem the run with five straight points for the Buffaloes but Wilcox continued to knock down shots. He hit another 3 when Williams-Goss broke the Colorado press and found him open in front of the Washington bench. He scored off a steal with a left-handed layup and hit another stand-still 3 for a 51-39 lead, his sixth straight make to start the second half.

Andrews added a driving layup to push the lead to 14 before Scott finally scored in the lane to briefly stop the run. Washington went up 18 when Wilcox knocked down his seventh 3-pointer with 6:42 left for a 61-43 lead, the largest of the game.

"I just think we have a lot of weapons and we play really unselfishly," Williams-Goss said. "It's been a big emphasis in practice, moving the ball and make sure the ball's not sticking. He was just the recipient of good ball movement and he's really good at moving without the ball."