LAS VEGAS -- Arizona suffered one of its worst losses of the Sean Miller era when it played at Oregon earlier this season.

The Wildcats will get a chance for revenge.

Forward Lauri Markkanen scored 29 points and guard Allonzo Trier added 20 as seventh-ranked Arizona advanced to the Pac-12 tournament championship game by beating No. 3 UCLA 86-75 Friday night.

Arizona (29-4) will play fifth-ranked and top-seeded Oregon in the Pac-12 title game at 11 p.m. ET. The Ducks romped in the only regular-season meeting between the teams, winning 85-58 in Arizona's largest margin of defeat since a 30-point loss to BYU on Dec. 28, 2009.

"I feel we're ready," said Arizona senior guard Kadeem Allen. "Everybody in this room knows what happened when we went up there. We're prepared. We're focused and we're putting all our chips into that game."

The Wildcats got to the title game on the strength of their defense and the one-two offensive punch of Markkanen and Trier.

Markkanen a 7-foot freshman, hit 10 of 21 shots from the field, including 4 of 10 from 3-point range -- as many long-range makes as the Bruins, who were uncommonly cold. He finished one off his career-high point total.

Trier was an efficient 5 of 8 from the field -- plus 7 of 10 from the line.

UCLA (29-4), which hits 41.3 percent from behind the arc for the season, made just 4 of 25 and saw its 10-game winning streak snapped. Half of its losses have come at the hands of Arizona, which won the season series 2-1.

The best rivalry in the West Coast got a little more heated with 0.9 seconds left when Arizona coach Sean Miller called a timeout up 11 points. That was apparently a form of payback for UCLA calling a timeout with one second left in a 77-72 win in Tucson on Feb. 25 after Bryce Alford sealed the game with two free throws.

Said Miller: "I think we learned from UCLA in that game -- just making sure your team is poised moving forward when they called their timeout late. We wanted to do the same thing. Make sure our team was poised moving forward."

Said UCLA coach Steve Alford: "I guess they're upset I called a timeout at their place. We made two free throws and I didn't mean disrespect at all. I just wanted to set my defense. But, apparently, he thought I was being disrespectful and that was a means of coming back at us. But I by no means meant any disrespect and that is what I told him after the game."

The Wildcats led by double-digits for most of the second half. UCLA entered as the nation's highest-scoring team, but too many of its stars had off nights against a tight Arizona defense.

Point guard Lonzo Ball, who suffered a reported thumb injury to his left hand in the first half, had eight points and six assists, shooting 1 of 6 from 3-point range, failing to control the game as he has so many times. The All-American entered the game leading the nation with 7.8 assists per game.

Guard Bryce Alford, a 44.9 percent shooter from behind the arc this season, missed his first seven 3-point attempts and finished 1 of 10 en route to five points. Forward TJ Leaf, on the mend from an ankle injury, scored 15 but fouled out with 4:23 left to further thwart a comeback attempt by UCLA.

Guard Isaac Hamilton led the Bruins with 20 points.

"We didn't play well this whole tournament," Alford said. "We didn't shoot the ball well against USC and we didn't shoot the ball well tonight. We haven't been able to practice the way we normally practice because TJ has been out. We just have to get everyone healthy."

Most of the game was played at an intense, frenetic pace in front of a pro-Arizona crowd of 19,224 at T-Mobile Arena. The Wildcats made 7 of 13 3-point attempts in the first half in taking a 41-35 halftime lead, and they pushed the advantage to 10 with two quick buckets to open the second half.

The lead never dipped below eight after that.

NOTES: NBA legend Julius Erving attended Friday night's semifinals, sitting courtside for Arizona-UCLA. He chatted with ESPN analyst Bill Walton; their teams battled in the 1977 NBA Finals. ... UCLA has made a school-record 327 3-point shots and is chasing the conference record of 350, set by the 2007 Oregon Ducks. ... Arizona PG Parker Jackson-Cartwright has made 21 of his last 31 3-point shots, including 1 of 2 vs. UCLA. ... UCLA PG Lonzo Ball has 252 assists, closing in on the school record of 256, set by Larry Drew II in 2013. ... Arizona G Allonzo Trier has scored at least 19 points in six consecutive games.