Gilbert Arenas and the Wildcats knock Brandon Miller and Butler off their feet. (AP)

Arizona got balanced scoring, strong rebounding and the tough defense it needed and pulled away for a 73-52 victory in the Midwest Regional.

The second-seeded Wildcats (25-7) won for the 17th time in 19 games and advanced to San Antonio for their fourth trip to the regional semifinals in the last six years.

"We have a shot if we keep our mind on our business and play the way we're capable of playing. We have a shot against anybody," Arizona coach Lute Olson said.

"We've just played some great defense the last month and a half."

Arizona shut off Butler's perimeter game that had been so effective in the Bulldogs' first-round rout of Wake Forest.

Butler had a seven-point lead late in the first half but Arizona erased that with an 11-2 spurt to close the half and then took over with 15-0 second-half run.

Butler's 3-point shooters couldn't get the shots they wanted and the Bulldogs went scoreless for nearly seven minutes during the second-half Arizona run.

After making 8-of-15 from the 3-point line in the victory over Wake, the Bulldogs managed just 6-of-26, including 2-of-16 in the second half.

"To shoot a good percentage you have to get good looks and in the second half Arizona just took away all our good looks. We wore down and our shots were short," said Butler's Brandon Miller, who had just four points after scoring 18 in the first round.

"That's definitely one of the best college basketball teams I've seen in a long time," Butler coach Thad Matta said. "They just took away every thing we wanted to do."

Gilbert Arenas scored 15 points, Michael Wright had 14 and Jason Gardner and the 7-foot-1 Woods 12 each for Arizona.

Getting a big lift off the bench from Luke Walton, who had 10 rebounds, the Wildcats dominated the boards, 39-20. They also had a big advantage at the foul line, hitting 17-of-18 to just 4-of-5 for Butler.

"We knew how good they were going to be," Walton said of Butler, which lost to Arizona for the second time this season.

"We knew just being Arizona wasn't going to matter to them. They were a good disciplined team and therefore defense was a focus. And that was right up there as one of best defensive performances of the season."

LaVall Jordan led 10th-seeded Butler (24-8) with 17 points, but had only five in the second half.

"We knew they would come at us on the inside," Jordan said. "We had some emotion in the first half but we died out some in the second half and we knew they would pound us on the inside."

After taking a four-point lead at the half, the Wildcats' quickness began to take over in the second.

Gardner beat the shot clock with a 3-pointer off a one-on-one move and after Arenas took an alley-oop pass from Richard Jefferson for a basket, Gardner made a steal and drove for a layup.

That gave the Wildcats a 43-34 lead with just over 15 minutes to go.

Leading by seven, the Wildcats then went on the 15-0 run as Butler became unglued.

Woods had a short jumper and later hit two free throws after an intentional foul call on Butler's Scott Robisch. The final nine points of the run came at the line and Arizona had a 58-36 lead with 7:13 to go.

The Wildcats beat Butler 72-60 in Tucson in December, although it was a four-point game with 90 seconds left.

This time, it wasn't that close and the Wildcats are moving on.