LAS VEGAS -- Arizona was not particularly crisp on offense and big man Deandre Ayton missed shots that normally fall for him.
None of it slowed the Wildcats on their way to the Pac-12 Tournament semifinals.
Scrappy and suffocating on defense, No. 15 Arizona rolled over Colorado 83-67 on Thursday in the Pac-12 quarterfinals.
"I really liked our defense, especially in the second half," Arizona coach Sean Miller said. "We had plenty of transition opportunities because of our defense and that's when we're at our best."
Ayton missed numerous shots near the rim, fouling out after scoring 10 points on 4-of-14 shooting and grabbing six rebounds. The Wildcats (25-7) were disjointed at times on offense, unable to find seams in Colorado's zone defense.
But Arizona was superb on defense most of the day, though, holding Colorado to 5-of-20 shooting from 3-point range and nabbing 11 steals, including four by Rawle Alkins.
"I thought our ball screen defense was good," Miller said. "Our team defense was good. We had a lot of players working together. I didn't really look at them having a lot of great looks that they missed. I think our defense was intact."
Colorado (17-15) managed to hang with the Wildcats well into the second half despite playing a tough opening-round game the day before. The Buffaloes suffered a huge blow with about 13 minutes left, when point guard McKinley Wright IV went down with a right ankle injury. Arizona reeled off 14 straight points and the Buffaloes never recovered.
George King had 19 points, and Lucas Siewart 16 for Colorado.
"McKinley goes out, it might take us a while to figure things out offensively, but we weren't getting any stops," Colorado coach Tad Boyle said. "They went on that run, and it was kind of all she wrote."
Arizona played through a season of turmoil, winning its fifth Pac-12 regular-season title in six years despite twice being linked to a federal investigation into shady recruiting practices.
Miller's job appeared to be in jeopardy late in the season, when an ESPN report alleged he was caught on an FBI wiretap discussing a $100,000 payment to lure Ayton to the school. Miller missed one game and three practices while the school investigated, but returned for the final two games after vehemently denying the report and the university president saying he will remain as coach.
The Buffaloes and Wildcats split during the regular season, each winning at their own arena.
Colorado used a big second-half run to beat Arizona State 97-85 in its Pac-12 opener, a game that put Boyle in a walking boot after injuring his right calf trying to break up a fight.
The Buffaloes made 13 of 21 from the 3-point arc in that victory and their hot shooting continued early against Arizona, making five of their first eight shots.
The Wildcats turned up the defensive pressure and that got their offense going -- not to mention the pro-Arizona crowd -- for a 15-2 run that put them up 27-19.
Colorado answered with a short run of its own, cutting Arizona's lead to 35-33 by halftime.
The Buffaloes kept Arizona close to start the second half, but suffered a huge blow with when Wright appeared to come down on someone's foot. He had to be helped off the court and didn't return.
The Buffaloes had a hard time getting into their offense without the freshman leader and Arizona took advantage, going on a 14-0 run to push the lead to 58-41.
"McKinley's a warrior," Boyle said. "I thought, if we could have gotten that thing within striking distance, I probably would have gone with him, but I certainly didn't want to risk him or his ankle for the sake of just putting him back in the game."
Colorado looked like it had a shot at hanging with the Wildcats until Wright's injury.
Arizona showed it doesn't have to fire on all cylinders or need a big game from Ayton to advance.
Despite Ayton dealing with foul trouble and not having a huge impact on the game, Arizona still controlled the glass against Colorado. The Wildcats had a 34-24 rebounding advantage and scored 10 second-chance points on 10 offensive rebounds.
"We were not good rebounding all night," Boyle said.
Colorado could end up in a smaller postseason tournament.
Arizona plays the Stanford-UCLA winner in the semifinals Friday.