The loss snapped the Wildcats’ (12-4, 2-1 Pac-12) nine-game winning streak, while Colorado (10-6, 2-2 Pac-12) was able to complete the sweep of the Arizona schools.
Ayton poured in 19 of his 26 points in the second half, drawing comparisons to Hakeem Olajuwon, Wilt Chamberlain, and Shaquille O’Neal by Bill Walton, but it wasn’t enough for Arizona to overcome a poor first half.
Stymied by Colorado’s zone — a rare look from CU coach Tad Boyle who calls zone defense “the dark side” — Arizona shot just 38 percent, including a dismal 7-24 mark from 3.
Arizona’s defense was not nearly as effective, as Colorado shot 55 percent and 7-16 from 3. Five Buffaloes scored in double figures.
That Arizona only lost by three is rather remarkable.
The Wildcats trailed 45-29 at halftime after shooting just 30 percent and 3-13 from 3 in the period.
Meanwhile, the Buffaloes not only were able to generate open look after open look, but they were making them, too, shooting 64 percent in the first half.
Arizona trailed by as many as 20 points in the period, leading Sean Miller to call three timeouts and empty his bench in search of a spark.
That sort of worked.
Emmanuel Akot hit a 3 to cut UA’s deficit to 17, then Keanu Pinder got into a scuffle with CU’s Dominique Collier that took some wind out of Colorado’s sails (because there was a lengthy review before double technicals were called).
Rawle Alkins spun and scored to cut Colorado’s lead to 14 with 45 seconds left in the first half, but Namon Wright hit a mid-range jumper to push the Buffs’ lead to 16 at the break.
Arizona often settled for 3s early in the shot clock instead of working its way inside. The Wildcats had just 10 points in the paint in the first half.
After Wright’s jumper, Arizona had 19 seconds to answer, but could not even get a shot off before the buzzer sounded — a microcosm of Arizona’s disastrous start.
Miller was unhappy with UA’s effort and energy, but it did improve in the second half when Arizona outscored Colorado, 48-35.
Arizona started on a 15-4 run to cut CU’s lead to 49-46 with roughly 12 minutes left.
Colorado was crisp on offense in the first 20 minutes, but committed 13 of its 15 turnovers in the second half.
That, plus 16 offensive rebounds, allowed Arizona to attempt 73 shots to Colorado’s 53, but the Wildcats couldn’t take advantage of the discrepancy.
Allonzo Trier had one of his worst games at Arizona on both ends of the floor, scoring just eight points on 3-9 shooting. He attempted eight 3s — most were contested and some early in the shot clock — and made just two.
Dusan Ristic had 13 points and 11 rebounds, but shot 6-16 and struggled defensively. Arizona insisted on feeding the ball to Ristic even though Colorado clearly had no answer for Ayton who shot 11-17.
Parker Jackson-Cartwright had eight assists but missed all six field goal attempts.
Alkins had 16 points on 6-14 shooting, but he missed several open 3s, shooting just 2-7 from that range.
After Arizona cut CU’s lead to three, the Buffaloes were able to extend it back to a 10-point advantage with 5:39 left.
The Wildcats chipped away from there, but were unable to get back within one possession until Ayton hit a jumper with less than one second to play.
By then it was too late and soon enough Colorado fans were pouring onto the court for the second time in three days.
Follow Ryan Kelapire on Twitter at @RKelapire