By Beth Harris
The Associated Press

ANAHEIM, Calif. - Kansas played well for 20 minutes against Arizona the last time the teams met in January. The Jayhawks' 20-point lead in the first half wasn't enough.

Arizona shot 53 percent in the second half when the Jayhawks' shooting slumped to 29 percent, and the Wildcats went on to a 91-74 victory that ended Kansas' 23-game nonconference winning streak at Allen Fieldhouse.

"If you play great basketball for 20 minutes and sorry basketball for 20 minutes, you lose by 17," Kansas coach Roy Williams said.

The rematch between the top-seeded Wildcats (28-3) and second-seeded Jayhawks (28-7) is at 7:05 p.m. ET in the West Regional final at Anaheim Arena. The winner advances to the Final Four.

"I don't think there's any advantage for us having beaten them or for them having lost because they know how they dominated us through about the first 15 minutes of that game," Arizona coach Lute Olson said.

Williams said the Jayhawks played perhaps their best half of the season along with their worst in the Jan. 25 game.

Kansas guard Keith Langford said the Wildcats were merely trying to hold on in the second half of the first game between the teams - something he hadn't seen before.

"They put pressure on us by attacking and making shots," he said. "Psychologically, if that game still has an effect on us, then we're probably not ready to play."

Arizona leads the nation in scoring with an 85.5-point average, and Kansas is third at 82.6.

But both coaches believe defense will determine the outcome.

"If we're aggressive on the defensive end and get in the passing lanes and make people do things they don't want to do, it could cause some problems," Arizona center Channing Frye said. "They do try to ram it down your throat. We're very quick and we need to get back on defense."

Kansas forward Nick Collison had a career-high 33 points and 19 rebounds in a 69-65 victory over third-seeded Duke in the regional semifinals Thursday night.

Olson said his team is playing its best ball of the season, and the Wildcats showed that Thursday night, using 22-3 and 16-3 runs in its 88-71 victory over fifth-seeded Notre Dame.

Olson noted the Jayhawks score a majority of their points off fast breaks.

"They're coming at you every time. The big guys run so well. Collison runs the court like a guard," he said. "They're not going to come down where you have a little time to relax and catch your breath."

Arizona senior Rick Anderson said the earlier victory over Kansas taught the Wildcats that they could be unbeatable if they played both halves equally well. The lesson was especially valuable for freshmen reserves Hassan Adams and Andre Iguodala.

"Kansas is a great ballclub and after beating them it gave us experience and confidence," Anderson said.

Arizona outrebounded Kansas 38-28 in January, when Wildcat guard Salim Stoudamire scored a career-high 32 points, including 20 in the second half.

"We have to do a better job of boxing out," Collison said.

Kansas has won five of the seven meetings between the teams including an 83-80 victory in the 1996 NCAA tournament. A year later, Arizona beat the Jayhawks 85-82 en route to winning the national title.