Arizona State had UCLA reeling, in position to send the top seed in the Pac-12 tournament home early.

Once freshman Shabazz Muhammad got rolling, the Sun Devils couldn't stop him or the Bruins.

Muhammad scored 12 of his 16 points in the second half and No. 21 UCLA rallied from a 15-point deficit to beat Arizona State 80-75 in the quarterfinals of the Pac-12 tournament on Thursday.

"Muhammad really was a difference maker down the home stretch," Arizona State coach Herb Sendek said.

Wearing new uniforms with sleeves and matching camouflage-patterned shorts that looked like pajamas, the Bruins (24-8) played like they were half awake well into the second half.

Muhammad gave UCLA the spark it needed with a highlight-reel dunk over Arizona State center Jordan Bachynski and scored 10 points during a 17-4 second-half run that got the Bruins back in it.

UCLA kept its composure down the stretch, going up 78-75 on Travis Wear's jumper with 11 seconds left and stayed in front when Arizona State's Jonathan Gilling missed a corner 3-pointer in the closing seconds to avoid becoming the second straight No. 1 seed to lose its first game in the tournament.

Larry Drew II had 20 points, Wear finished with 15 and Muhammad had six of UCLA's 15 offensive rebounds — nine total — to send the Bruins into the semifinals against No. 18 Arizona or Colorado on Friday night.

"These guys never quit. They never gave up," UCLA coach Ben Howland said. "They never stopped believing in themselves and each other and really found a way to battle back. "

Jahii Carson had 21 points, seven assists and six rebounds to lead ninth-seeded Arizona State (21-12). Bachynski had 22 points and Gilling 17 for the Sun Devils, who have to wait until Sunday to see if they'll get an at-large bid to the NCAA tournament.

"Anytime they had an open look down the home stretch, they made it," Sendek said. "They didn't let us off the hook. Whether it was Drew, the Wear brothers, anytime we had a breakdown, there was no forgiveness on their part. They were making shots."

UCLA won its 31st conference championship by beating Washington in the season finale to finish 13-5 in the Pac-12. The Bruins had some bumpy stretches along the way, losing three of four in January and to struggling Washington State three days before the clincher against the Huskies.

UCLA got the No. 1 seed and a first-round bye in the Pac-12 tournament, but drawing Arizona State in the quarterfinals was not an ideal first game.

The Bruins were blown out by the Sun Devils in Tempe and needed overtime to escape with a win at Pauley Pavilion.

Arizona State needed overtime to hold off Stanford in its tournament opener, but seemed the fresher team early in the quarterfinals, breaking down the Bruins off the dribble and getting the ball inside.

Bachynski had 22 points and 15 rebounds in Arizona State's blowout victory and the Sun Devils fed him early and often. The 7-foot-2 Canadian scored 10 points in the opening 10 minutes, forcing UCLA to start double teaming him down low.

Bachynski had 14 points on 4-of-6 shooting by halftime.

Carson wasn't bad, either.

The redshirt freshman had a huge game in the Sun Devils' opener, scoring a tournament freshman record 34 points, including five in overtime. He was active and aggressive against UCLA, repeatedly getting into the lane for one-handed runners high off the glass or finding teammates for open shots.

Carson had 11 points and four assists in the first half and the Sun Devils hit 15 of 28 shots to lead 41-33.

Muhammad was uncharacteristically quiet for UCLA, unable to shake Carrick Felix to get good looks at the basket. He had four points — two on a putback at the buzzer — on 2-of-5 shooting in the first half.

After UCLA trimmed the lead to 3, the Sun Devils tried to run away with it, scoring 10 straight points to go up 53-38.

Then Muhammad woke up.

After missing his first four shots of the half — two blocked by Bachynski — he scored 10 points in a little over 5 minutes, including an emphatic tomahawk dunk over Bachynski on the break.

Led by their fabulous freshman, the Bruins stormed back, going on the big run that Drew capped with a 3-pointer to put UCLA ahead 67-66 with 5 minutes left.

Arizona State kept it close and had a chance at the end, but Gilling's 3 bounced long and the Sun Devils couldn't come up with the rebound, possibly leaving them short of a trip to the NCAAs.

"It's really disappointing," Bachynski said. "That was our goal all season. That's what we worked toward. Nothing else really to say."