LOS ANGELES - By the time Oregon State's Joe Burton was banished to the locker room, with MoMo Jones and a whistle ringing in his ears, the Beavers' swagger finally disappeared.

For the Arizona Wildcats, who beat OSU 78-69 in a Pac-10 tournament quarterfinal at Staples Center on Thursday, it was about time.

The Beavers have managed to get under the Wildcats' skin more than just about every other Pac-10 team. That may even include USC, which will face Arizona tonight in the Pac-10 tournament semifinals with a coach who says UA standout Derrick Williams is the "most protected dude since Michael Jordan."

The lightly regarded Beavers managed to beat Arizona three straight times before the Wildcats stopped them 70-59 last week at McKale and, for over 10 minutes early Thursday, OSU was having its way again.

With the Beavers running their trademark zone defenses, artfully athletic OSU wing Jared Cunningham repeatedly popped in the passing lanes to steal balls and convert them for easy scores.

Arizona trailed the Beavers for 12 minutes and the Wildcats committed a total of nine turnovers in the first half.

"That's what they look to do," Williams said. "They trap the ball. They get you in the corners and they make you throw lackadaisical skip passes. I caught myself doing that, as well as my teammates."

But, with his body language and smooth three-point shooting touch, Williams began to change the momentum. After his third three-pointer of the first half, Williams gestured to the Oregon State bench, and the Wildcats went steaming into the locker room with a three-point lead.

Then they quickly expanded it in the second. After halftime, Jones hit two quick three-pointers and Williams added another for a 49-39 lead with 17:39 left.

From there, the Beavers never cut the margin to a basket again. They trailed by up to 17 points after Burton was tossed for flagrantly fouling UA forward Kevin Parrom with 10:25 to go.

Burton said afterward he felt he was instigated by Parrom, who said he "was just being physical."

Parrom said "it would be selfish" if he responded by charging or speaking to Burton, and UA coach Sean Miller praised his restraint.

"I thought Kevin handled himself with a lot of poise," Miller said. "That's not always an easy situation to handle."

After reviewing the play, officials whistled Burton for the flagrant foul that resulted in an immediate ejection, while Burton and Jones were also whistled for offsetting technical fouls when they jawed in the aftermath of the incident.

"It was X-rated," Jones said, smiling, of his conversation with Burton. "It was just that Kevin is my boy, that's my teammate. You stick up for what's in your circle. I didn't see the play but I saw Kevin kind of rolling around and I just had a few words with him. We exchanged words."

OSU coach Craig Robinson said afterward he didn't get to see the play either, and declined to comment in depth.

"I couldn't see the screen. I just heard the crowd," Robinson said. "It was a physical game, and I'm sure there was something leading up to that. But I don't want to take anything away from the University of Arizona. I don't want to take anything away from Joe's play. He was playing a good game up until then, and we certainly missed having him in there."

Without Burton, the Beavers gave up eight straight points and the game was essentially over.

Parrom wound up hitting only 1 of 2 free throws for the foul to give UA a 61-51 lead but the Wildcats scored seven more points, on two baskets from Parrom and a three-pointer from Williams, to give UA a 68-51 lead with 7:46 that all but put the game away.

Williams finished with 22 points and seven rebounds to lead Arizona, while Cunningham had 23 points, six steals and four assists as Oregon State ended its season at 11-20.

Arizona (26-6) will get to continue its season next against USC (19-13), which beat UA 65-57 on Feb. 24 just two days after Trojans coach Kevin O'Neill hinted not so subtly that Williams was getting some help going to the free-throw line.

Perhaps not coincidentally, Williams shot just two free throws in that game at Galen Center and was whistled for four fouls.

Williams said after the loss to USC last month that officials may have listened to O'Neill, but when he was asked about that Thursday, Miller interrupted.

"I'll answer that question," Miller said. Today's game "is about USC and Arizona. Players on both sides are outstanding and it's a game that means a lot to get to the championship. No one here's going to answer the question about the officials or something that was said. I think that period of time is over."

After the interviews were over, Williams indicated he has moved on, too.

There were "just a couple calls that I thought weren't fouls," Williams said of the last USC-UA game. "But you just gotta get over it and keep playing."

On StarNet: See more photos from the action at Staples Center at azstarnet.com/gallery


• What: No. 1 Arizona vs. No. 4 USC

• When: 7 p.m.


• Radio: 1290-AM, 107.5-FM

Full Pac-10 tournament schedule on Page B4

Men's Pac-10 tournament

At Staples Center, Los Angeles; all games on FSAZ unless noted.

First round, Wednesday

• Game 1: No. 9 Oregon State 69, No. 8 Stanford 67

• Game 2: No. 7 Oregon 76, No. 10 ASU 69

Quarterfinals, Thursday

• Game 3: No. 4 USC 70, No. 5 California 56

• Game 4: No. 1 Arizona 78, No. 9 Oregon St. 69

• Game 5: No. 7 Oregon 76, No. 2 UCLA 59

• Game 6: No. 3 Washington 89, No. 6 Washington State 87

Semifinals, today

• Game 7: No. 1 Arizona vs. No. 4 USC, 7 p.m.

• Game 8: No. 7 Oregon vs. No. 3 Washington, 9:30 p.m.

Championship, Saturday

• Game 9: Game 7 winner vs. Game 8 winner, 4 p.m., Channel 13