LAS VEGAS – Lauri Markkanen scored 20 points, Allonzo Trier added 19 and No. 7 Arizona pulled away in the second half for a 92-78 victory over Colorado on Thursday night in the Pac-12 Tournament quarterfinals.

Arizona (28-4) had a hard time shaking the Buffaloes in the first half before stretching the lead to 17 in the second.

The co-Pac-12 champions shot 56 percent, made 10 3-pointers and held nearly everyone except Derrick White in check on defense.

Dusan Ristic added 15 points for the Wildcats, who will play the winner between No. 3 UCLA and Southern California in Friday’s semifinals.

White finished with 31 points and Xavier Johnson had 20, but Colorado (19-14) had no answer when Arizona hit the gas in the second half.

BOX SCORE: Arizona 92, Colorado 78

Arizona shared the Pac-12 title with Oregon and was the No. 2 seed in the conference tournament after losing to the Ducks in Eugene.

The Wildcats won the only regular-season meeting with Colorado 82-73 in Tucson behind Kadeem Allen’s stellar game at both ends.

The Buffaloes earned another shot at Arizona and a potential NCAA Tournament resume-boosting win after knocking off Washington State in the quarterfinals.

The first half of the rematch turned into a duel between White and Trier. White had 15 points, Trier scored 12 and the Wildcats had a 38-37 lead at the break.

Arizona turned the second half into a rout. The Wildcats opened with an 11-0 run to push their lead to 12 points.

Colorado tried to fight back with a 6-0 run, but Rawle Alkins and Markkanen hit consecutive 3-pointers to make it 60-47.

The Buffaloes cut it to nine after that, but got no closer.