No team has won more Pac-10 tournament titles than Arizona. Based on the surprise success the Wildcats enjoyed during the regular season, another championship could be within reach.

The top-seeded and No. 16 Wildcats begin their quest for a fifth conference tournament championship Thursday night against Oregon State in a quarterfinal matchup in Los Angeles.

After going 16-15 and missing the NCAA tournament for the first time in 26 years in 2009-10, Arizona (25-6) enjoyed a remarkable turnaround in Sean Miller’s second season as coach. The Wildcats went 14-4 in the league to win their first regular-season title in six years.

“It’s amazing. It’s the reason I came here. It’s the reason we all came here,” said forward Derrick Williams, the Pac-10 player of the year averaging 18.8 points and 8.2 rebounds. “It’s the first step and now hopefully we can win the Pac-10 (tournament) championship, too.”

Though Arizona has the most wins in tournament history, it has not won the title since 2002, when the event returned after an 11-year hiatus. The Wildcats, who won three straight titles from 1988-1990, look to snap a three-game tournament skid that followed an 87-56 win over Oregon State in the first-round of the 2008 event.

While Arizona might be the favorite this weekend, it should be in for a challenge against the ninth-seed Beavers (11-19).

One of Oregon State’s five regular-season league wins came at home where it sank some late free throws to beat Arizona 76-75 on Jan. 2. The Wildcats avenged that defeat with a 70-59 win last Thursday in the first of two victories over the Oregon schools to conclude the regular season after losing at UCLA and Southern California the previous week.

Oregon State did a decent job in both games of containing Williams, who totaled 31 points and 14 boards over the two meetings. The Beavers will obviously be in for a challenge to do it again, though the 6-foot-8 sophomore has averaged just 13.0 points the last four games.

As a likely NBA lottery pick, it’s possible Williams could be consumed by the constant talk of whether he’ll leave school early after this season. He insists that’s not the case.

“I just want to win, that’s all I can say about that,” said Williams, who was 11 for 14 from the field this season against Oregon State but 8 for 20 from the foul line. “That’s my focus for right now.”

Oregon State’s focus will be on trying to maintain the momentum it earned after snapping a five-game tournament skid with a 69-67 first-round victory over Stanford on Wednesday. It was the Beavers’ first victory in the event since beating Arizona State in 2006.

“I can’t tell you how excited we are to get our first Pac-10 Tournament win in this era,” Oregon State coach Craig Robinson told the Pac-10’s official website. “It’s been a while and it sure feels good.”

Sophomore guard Jared Cunningham scored 24 points, including 15 of 20 free throws, and Devon Collier added 10 as the Beavers held the Cardinal to 32.8 percent shooting.

Cunningham is averaging a team-leading 13.9 points this season, but only 8.8 in four games versus Arizona.