Siewert came off the bench for a team-high 17 points for the Buffaloes (15-10, 7-6), who swept California and Stanford this week to run their winning streak to three games.

Dorian Pickens went for a game-high 18 points for the Cardinal (13-13, 7-6), which went winless on its two-game trip to Utah and Colorado.

Colorado led just 15-13 before McKinley Wright IV and Siewert ignited the early run-away with layups.

The four 3-pointers came in succession, with Siewert hitting two while Collier and King dropped in one apiece, completing the run that opened a 31-16 lead late in the first half.

Colorado led 31-20 at halftime.

Down by as many as 14, Stanford rallied in the second half, closing within 39-34 on a layup by Daejon Davis will 13:20 to play, 45-42 on a 3-pointer by Pickens with 9:01 left and eventually within one on two occasions, the final time on a layup by Davis with still 5:47 remaining.

But the Buffaloes had an answer for every challenge, including a key 3-pointer by Siewert with three minutes left when Stanford was still clinging to life, down just 56-52.

Siewert connected for four 3-pointers, matching Pickens' total.

Wright had 10 points and King added nine to go with a game-high nine rebounds for the Buffaloes, who have held their opponents to an average of just 58 points per game during their winning streak.

Wright also recorded a game-high seven assists for Colorado, which has gone 6-1 at home in conference play.

Davis had 12 points and a game-high four steals, and Reid Travis added 10 points for the Cardinal, which was held to 60 and 56 points on their trip after having scorched the nets for 80 and 96 in consecutive wins over Oregon State and Oregon last week.

Stanford has lost four in a row on the road in the conference after sweeping Washington State and Washington on a trip in January.

--Field Level Media