San Jose, Calif. ? Kareem Rush and Clarence Gilbert demonstrated what everyone in the West Regional already suspected: Missouri is no ordinary 12th seed.

Gilbert scored 17 of his 23 points in the second half, and Rush scored 20 points to help the Tigers roar to their third upset of the tournament, beating eighth-seeded UCLA, 82-73, Thursday night.

Missouri is the first 12th-seeded team to reach the round of eight since the NCAA Tournament expanded to 64 teams in 1985.

Arthur Johnson had 14 points and 13 rebounds for the Tigers (24-11), who advanced to face Oklahoma on Saturday in an all-Big 12 regional final.

Missouri, ranked as high as No. 2 early in the season before slumping during conference play, is headed to the final eight for the first time since 1994. The Tigers broke open a close game with tough defense and a barrage of outside shots by Rush and Gilbert, who each hit four three-pointers  seven of them after halftime.

Given the Tigers’ struggles during a tumultuous campaign, coach Quin Snyder wasn’t surprised to see their impressive resolve down the stretch.

“We drew on our adversity during the hard times,” Snyder said. “We talked about it in the huddles. We talked about it on the court  how we weren’t going to let the adversity get in the way.”

Matt Barnes scored 16 of his 23 points in the second half for UCLA (21-12), which has reached the regional semifinals in five of six seasons under coach Steve Lavin, but won there just once.

The Bruins led much of the game, but wilted under the second-half pressure of Missouri’s remarkable outside shooting.

UCLA was ahead 57-54 with 10 minutes to play, but Rush and Gilbert propelled a 19-6 run that put it away before the final minutes.

“Coach was telling me the whole second half: ‘If you’re open, shoot it!”‘ Rush recalled with a grin. “We finally got a few shots to go down … but that run happened because we started playing defense. Coach told us to buckle down, and we finally did.”

Gilbert, the Big 12’s top 3-point shooter, dislocated his finger in the opening seconds, but shook it off for another outstanding game.

“I looked at Coach, and he said, ‘It’ll be all right. Pop it back in,”‘ Gilbert said. “You knew this was big.”

At the final buzzer, the Tigers embraced each other and Snyder, who answered the critics of Missouri’s late-season slide with a trip to the regional final in just his third season.

Rickey Paulding had 15 points for Missouri, while Johnson played a solid inside game against UCLA’s Dan Gadzuric.

The Tigers were led by Gilbert and Rush, who flourished under Snyder’s instructions to shoot early and often. Missouri made more 3-pointers per game this season than all but five Division I teams.

Billy Knight had 16 points for UCLA in his final game. Knight, Gadzuric and Barnes all finished their careers with another difficult tourney loss.

Jason Kapono, UCLA’s leading scorer, managed just seven points against a Missouri defense designed to stop him. Only Barnes, who scored nine straight points for the Bruins early in the second half, appeared up to the challenge of facing a more physical Big 12 defense.

Led by Barnes, UCLA twice was ahead by eight points in the second half before Gilbert and Rush got going. Rush’s fourth 3-pointer of the half gave the Tigers a 63-59 lead with 7 minutes left, and Gilbert capped the night with his fourth 3-pointer 3 minutes later, giving Missouri a 10-point lead.

Both teams were highly regarded early in the season  UCLA rose as high as No. 3 in the rankings  before faltering. But both got on track at the right time, with Missouri ripping through Miami and Ohio State last weekend, while UCLA upset top-seeded Cincinnati in double overtime in the second round.

In the schools’ only previous NCAA tournament meeting, in 1995, UCLA won on Tyus Edney’s length-of-the-floor drive for a buzzer-beating layup. The Bruins went on to their 11th national title, with Lavin watching from the sidelines as Jim Harrick’s assistant.

The Missouri players claimed no interest in getting revenge for that loss, but the Tigers’ fans in San Jose clearly appreciated the gesture.

Missouri, which led for all but 2 minutes of its first two tournament games, trailed for most of the first half Thursday until Paulding’s jumper gave the Tigers a 30-28 halftime lead.

UCLA shot just 31 percent before halftime, but Missouri made 10 turnovers.