LAS VEGAS - After two troubling regular-season losses to UCLA, the Arizona Wildcats will get another crack at the Bruins today.

It might as well be now.

While beating Colorado 79-69 Thursday in the Pac-12 tournament semifinals, the Wildcats appeared as ready as they have been to face the league champs since, oh, maybe Christmas.

"I can't wait," said UA guard Nick Johnson, who led the No. 18 Wildcats both offensively and defensively. "They got us two times during the season so it's definitely a great challenge. I'm looking forward to it."

Nobody exemplifies better why UA is ready than Johnson. The sophomore known as "Bunnies" was back in full energy mode for the second straight game, collecting 18 points over 35 minutes and helping keep Colorado's Spencer Dinwiddie to 4-for-12 shooting.

The Wildcats also had offensive balance, with UA reserves chipping in 25 points. That included eight points from Brandon Ashley and two three-pointers from reserve guard Jordin Mayes, who is finally showing the kind of confidence that made him a deadly shooter in the 2011 NCAA tournament.

Defensively, the Wildcats aggressively dealt with Colorado's ball screens, kept guards Dinwiddie and Askia Booker relatively in check and collected seven steals and seven blocks.

So, UCLA? Why not?

"It's coming at a great time," senior forward Kevin Parrom said. "We have Nick playing back to form again. You can see the difference. When everybody does their role, we're fine. Brandon is playing well. Kaleb (Tarczewski) is playing well. Even Mayes is playing like (2010-11)."

"That Texas game (when Mayes was 4 of 4 from three)? I'm sure you remember that."

The way UA coach Sean Miller views it, though, all of those factors must be present today. He said the Wildcats would have to play their best performance of the season to beat the Bruins.

But he also has a team that believes it can do exactly that, speaking with a confidence that hasn't often been seen since Johnson swatted away a shot to save Arizona's Diamond Head Classic victory over San Diego State on Christmas Day.

"We just played hard. We played together," Mark Lyons said. "We shared the basketball. When somebody was open, they got the ball. When we play like that we're tough to beat."

Lyons played a central role in both getting and giving the ball while the Wildcats held off Colorado in the final minutes.

UA built second-half leads of up to 14 points but Colorado cut it to 68-64 with 2:41 left, before Lyons twisted to hit a three-pointer from the left corner as the shot clock dwindled down.

He missed seven of the first eight threes he took, but hit a difficult one when it mattered the most.

"It felt good," Lyons said. "I felt like all my (earlier) shots were a little short and flat."

Then, after Andre Roberson made two free throws to cut UA's lead to just 71-69 with 1:03 left, UA took the ball in a spot where Lyons has often taken the shot this season.

But this time, he did not.

"Usually I would take a shot or look for Solomon" Hill, Lyons said. "But Nick was having a great game.

"I said, 'You know what? He's going to score.' So I gave him the ball and he scored. I knew he was going to make a great decision with the basketball."

Johnson found himself isolated on the right wing, with only the 6-foot-1-inch Askia Booker in his way, and said he knew it was time to drive.

"Cheeks (Lyons) is usually our big shot-maker and he trusted me to iso me on the wing," Johnson said. "I just took advantage of Booker being smaller than me and finished the shot."

Johnson's driving shot near the basket put UA up by four and the Wildcats expanded the lead by hitting all six free throws they took while Colorado fouled in the final 24 seconds.

Johnson finished with an ultra-efficient line of 18 points on 6-for-7 shooting, 4-of-5 free-throw shooting, along with three assists, a block, a steal and only two turnovers.

Lyons needed 13 shots to get his 14 points, but also had three assists and a steal to two turnovers. And Hill, as usual, came through with 13 points and seven rebounds.

But it was also the four guys off the bench - Mayes, Ashley, Grant Jerrett and Angelo Chol - that particularly drove Colorado nuts.

The Buffaloes struggled inside after center Josh Scott picked up two early fouls and replacement Shane Harris-Tunks suffered a concussion when he fell to the floor after tangling with Jerrett.

"We've had two blatant no-calls that have led to concussions on our basketball team and I'm really disappointed about it," said Colorado coach Tad Boyle, referring also to the concussion Scott suffered against ASU last month.

Lightly used Ben Mills helped Colorado inside, with two rebounds and a free throw in five minutes but he didn't make a difference off the bench like Ashley and Jerrett.

"They've got the most quality depth of anybody in our league," Boyle said. "That (Angelo) Chol kid is a hell of a player and he didn't even get to play much tonight."

Defensively, Arizona also shared the load. Six players had at least one steal while Jerrett had four blocks in 21 minutes. The Wildcats forced 13 Colorado turnovers - 10 in the first half - and scored 17 points off those turnovers.

But disrupting UCLA, with the point guard that Miller called the MVP of the Pac-12 this season, figures to be a bit more difficult.

"Larry Drew (II) has been a huge reason why we've lost both games," Miller said. "He has scored and he's also gotten his teammates easy baskets. We have to be able to contain him. We have to be able to make sure that he doesn't control the game at the end of the clock, at the end of the game."

Offensively, UA's challenge could be just as difficult. In their two previous games against UCLA, the Wildcats shot 40.9 percent from the field and averaged 15 turnovers.

"We have to be really unselfish, move and create good shots," Miller said. "I think that anytime a team beats you twice, you really want to get that one win. So we're going to give it our best shot."

On StarNet: Join your fellow fans for a live chat during today's Pac-12 tournament semifinal at

See more photos from Arizona's win over Colorado at

Semifinals today

Game 1

• No. 18 Arizona vs. No. 21 UCLA: 6 p.m. on Pac-12 Arizona, 1290-AM and 107.5-FM

Game 2

• Utah vs. Oregon: 8:30 p.m. on ESPN and 1490-AM