LAS VEGAS (AP) Oregon is at its best playing fast, creating havoc and turnovers with its pressure defense.
The Ducks didn't do that in the first half against Colorado. Once they did get going, it was like a wave washed over the Buffaloes.
Joseph Young scored 30 points, Elgin Cook added 20 and Oregon rode a big second-half run to beat Colorado 93-85 in the Pac-12 tournament quarterfinals Thursday night.
''We didn't do a good job of maybe getting them to settle down and relax to start that ballgame,'' Oregon coach Dana Altman said. ''But I thought once we got into a flow and we made plays for each other ... the second half it was much better.''
Second-seeded Oregon (24-8) broke out from a tight game with its pressing defense, creating a string of turnovers to build an 18-point second-half lead.
No. 10 seed Colorado (15-17) made a late charge, but the Ducks held on to earn a spot in Friday's semifinals against Utah or Stanford.
Jalil Abdul-Bassit added 15 points for Oregon, which scored 27 points off Colorado's 13 turnovers.
''We came out, played very well, rebounded, played defense, was way more active the second half,'' said Young, the Pac-12 player of the year who also had seven rebounds and four assists.
Josh Scott had 16 points and Dominique Collier added 14 for the Buffaloes, who scored two points off Oregon's eight turnovers. Askia Booker had 12 points, five rebounds and five assists.
''I think the way we played in the first half, we all know we were capable of winning this game,'' Colorado coach Tad Boyle said. ''We didn't get it done.''
The Ducks put themselves inside the NCAA Tournament bubble with a strong finish to the regular season, winning nine of their final 10 games.
Among those wins was a 73-60 victory over Colorado on Feb. 18.
The Buffaloes needed to win four games in four days at the Pac-12 tournament to get into the NCAA bracket, something they did on the way to the conference title in 2012. Colorado took the first step in Wednesday's opening round, knocking off No. 7 seed Oregon State 78-71.
The Buffaloes carried the momentum from that game into the quarterfinals, attacking the Ducks from the start.
Colorado was crisp on offense early, handling Oregon's press and working the ball around for good looks while building an early 11-point lead.
The Ducks missed their first eight 3-pointers before hitting two from behind the arc in 11 seconds during a 13-2 run that tied the game at 31-all.
Colorado led 37-34 at halftime, but the Ducks went on another flurry in the second half by creating turnovers with their pressure.
The Buffaloes turned it over five times in a little over four minutes against Oregon's press and the Ducks turned each one into points, going on a 14-1 run to take a 60-47 lead.
The Ducks pushed the lead to 18, but Colorado made one last push, hitting four of five shots to cut the lead to 78-71 with about 3 minutes left.
Colorado pulled within 80-76 on a layup by Booker, but Young scored on a drive and the Ducks hit enough free throws down the stretch to close it out.
''This game's a little bit a microcosm of our season in the fact that we're not able to sustain really anything for an extended period of time,'' Boyle said.
Colorado: The Buffaloes had a 30-5 advantage in bench points.
Oregon: The Ducks made 22 of 29 shots in the second half and shot 53 percent overall.
Colorado's season is likely over.
Oregon will face the winner between Utah and Stanford in Friday's semifinals.