LAS VEGAS -- Arizona forward Lauri Markkanen had not seen his 3-point shots go through the rim so much in quite a while.

But it was only a matter of time.

The 7-foot freshman broke out of his shooting slump en route to a team-high 20 points as the hot-shooting, seventh-ranked Wildcats beat Colorado 92-78 in a Pac-12 quarterfinal on Thursday night at T-Mobile Arena.

"A couple of bad games doesn't define who he is as a shooter," said Arizona point guard Parker Jackson-Cartwright. "We knew it would take only one to really get things clicking again, and that's what happened tonight."

Markkanen, who was shooting better than 50 percent from 3-point range through 23 games, made just 5 of 28 from behind the arc in the final eight games of the regular season. The first-team All-Pac-12 player drilled 4 of 7 against Colorado.

He will be trying to keep that hot hand in the postseason while blending in his recent more physical play around the basket. That combination makes him a nearly unstoppable offensive threat.

"I'm trying to make sure I'm not just staying behind the 3-point line," said Markkanen, who is often compared to a young Dirk Nowitzki. "I'm trying to be versatile."

Second-seeded Arizona (28-4) showed plenty of versatility Thursday night as it advanced to play third-seeded UCLA in the semifinals.

The Wildcats shot 55.6 percent from the field (30 of 54) and 52.6 percent (10 of 19) from 3-point range to more than offset the individual brilliance of Colorado's Derrick White. The senior poured in 31 points after scoring 26 in an opening-round tournament victory over Washington State.

"This guy's going to be pro. There is no doubt about it," said Colorado coach Tad Boyle. "I think he's an NBA player, personally. I think he showed that tonight against a high-level defensive team, against high-level defenders."

Forward Xavier Johnson (20 points) was the only other Colorado player to make more than three baskets.

"Yeah, we need to have more balance," Boyle said. "It was tough. There is no doubt. I couldn't be more proud of the fight our guys showed, but we just weren't good enough tonight."

Colorado (19-14) likely will miss the NCAA Tournament for the second time in the past six seasons.

Arizona guard Allonzo Trier scored 19 points, while center Dusan Ristic and guard Rawle Alkins added 15 apiece. Guard Kadeem Allen had 13.

Arizona opened the second half with an 11-0 run as Colorado didn't score until 15:36 to go, when White made two free throws to cut the deficit to 49-39. The Buffs missed their first six field-goal attempts of the half.

Colorado was within 54-47 before back-to-back 3-pointers by Alkins and Markkanen started a 12-4 Arizona run. The surge gave the Wildcats enough room to stiff-arm a spirited Buffaloes squad that made five 3-point shots in the final 10 minutes.

"Let me tell you, they're a tough out," Arizona coach Sean Miller said of Colorado. "It was a good test for our team."

Arizona led by as many as nine points in the first half but relinquished the advantage late. Colorado surged with back-to-back 3-pointers from Josh Fortune and White -- the Buffs' only makes from beyond the arc in the half -- as part of an 8-0 run to take a 37-36 lead.

Ristic flipped in a short jumper with 10 seconds left as Arizona regained the lead, 38-37, at halftime.

NOTES: The Pac-12 announced the final two sessions of the league tournament -- the Friday night semifinals and the Saturday final -- are sold out at the 18,000-seat T-Mobile Arena. The tourney moved from the smaller MGM Grand Garden Arena for this season. ... Arizona and Colorado have met in five of the past six league tourneys. Arizona is 4-1 vs. the Buffs in the postseason. ... Arizona PG Parker Jackson-Cartwright has made 19 of his past 29 3-point shots, including 1 of 2 vs. Colorado. The junior, listed at 5-foot-11, had a career-high seven rebounds Thursday night, as well as seven assists. ... Four of Colorado's top five players in minutes played this season -- G Derrick White, F Xavier Johnson, F Wesley Gordon and G Josh Fortune -- were seniors.