LAS VEGAS Jackson Shelstad scored 21 points, Jermaine Couisnard had 20 and Oregon shut down No. 6 Arizona for a 67-59 victory on Friday night in the Pac-12 Tournaments semifinals.

The fourth-seeded Ducks (22-11) will play No. 22 Washington State or Colorado in Saturday’s championship game.

Arizona (25-8) will learn its seed and destination in the NCAA Tournament on Sunday. The Wildcats, who were 11 1/2-point favorites according to FanDuel Sportsbook, were attempting to become the first team to three-peat as Pac-12 champions since they won four straight in 1988-90 and 2002. There were no conference tournaments between 1991-2001.

N’Faly Dante had 14 points and 10 rebounds for Oregon, overcoming a tough early fall.

Oumar Ballo had 14 points and 12 rebounds for top-seeded Arizona. It was his 18th double-double this season.

Pelle Larsson added 11 points, but Pac-12 Player of the Year Caleb Love was held to six points on 2-of-11 shooting.

T-Mobile Arena has been dubbed McKale North for Arizona fans, but the Wildcats suffered their first tournament loss in three seasons under coach Tommy Lloyd. They are 7-1 in the conference tournament and 10-2 under Lloyd in Las Vegas. The other Vegas loss also occurred this season, a 96-95 double-overtime setback against then-No. 14 Florida Atlantic in December.

Oregon threatened to run away in the second half, taking a 61-48 lead before Arizona stormed back with a nine-point run. Four points came on one possession a blocking foul and a technical on the Ducks’ bench protesting the call.

But Arizona’s rally fizzled from there.

The Wildcats appeared on the verge of blowing open the game in the first half, going on an 11-point run to take a 27-13 lead with 6:52 left. They didn’t make a basket again until 3:01 into the second half a stretch of 9 minutes, 53 seconds. Arizona also had 5:52 stretch in the second half without a basket.

Oregon nearly lost center Dante, a two-time first-team all-conference player, to an apparent back injury just 1:02 into the game. He fell over Ballo before the Arizona big man dunked for the Wildcats’ first points. Dante, who missed 14 games this season to injuries, was helped to the locker room. He returned with 7:41 remaining in the first half.