MINNEAPOLIS -- Gilbert Arenas and Jason Gardner cheated into the passing lanes. As a result, the Wildcats prospered.

On consecutive Michigan State trips down the court in the second half, each picked up steals and finished on the other end -- Arenas with a pass to Richard Jefferson for a dunk and the other by finishing with his own layup.

And like that, those two plays had snuffed out the last Michigan State rally, taking a 10-point Arizona lead back up to 15 with 6:41 remaining.

But these two defensive plays epitomized the Wildcats' defensive effort throughout the game.

	Arizona's Jason Gardner found out he should stay in school instead of risk sinking out of NBA sight.

Michigan State's defense was supposed to be the story entering the teams' NCAA Tournament national semifinal game Saturday night. But it was Arizona's much-maligned perimeter defense that led to the Wildcats' 80-61 victory in the Metrodome.

"Some of the passes looked open," Michigan State's Charlie Bell said. "They did a great job reacting to the ball no matter what they were in either man or zone."

Jefferson got the 'Cats going with a phenomenal block on Jason Richardson to set the tone. The 'Cats then caught the Spartans off guard with a few switching defenses, from man-to-man to a matchup zone to a fullcourt pressure they used only one other time during the tournament -- against Eastern Illinois in the first round.

"People are shocked about our defense, but we've held teams to under 40 percent and not a lot of teams have done that against the kind of schedule we've played all year," Arizona coach Lute Olson said.

Arizona had Michigan State off guard in the first half with the switching defenses, but the Wildcats only held a two-point lead. A 21-3 run to start the second half, however, was the decided turn for the 'Cats. The spurt included a 14-0 stretch -- the most consecutive points the Spartans have given up this season.

Arenas finished with six steals -- a semifinal record. The Wildcats had 12 overall and forced 15 Michigan State turnovers.

"We had to have scored off 10 of those 12 steals," Olson said.

Arizona actually scored 21 points off the 15 steals, as the Spartans seemed to be staggered by the Wildcats' second-half defense.

"They got their fast break off turnovers and our No. 1 key was points off turnovers," Michigan State coach Tom Izzo said. "I give Arizona a lot of credit. But I'm totally confused as far as our turnovers, how we had them and what we did."

The Wildcats began to win this game in preparation. They studied the Spartans and anticipated the passes from Marcus Taylor, David Thomas and Charlie Bell. They always seemed to be in the right place at the right time.

During that 21-3 run, the 'Cats were even playing with more aggressiveness for loose balls. Zach Randolph got swallowed in the post while trying to get off an offensive rebound and when he lost control of the ball, Gardner was on the floor, scooping up the loose ball for a fast-break layup. He converted, got fouled and gave Arizona a 44-30 lead.

"We took the wind out of them," Jefferson said. "We just made the right reads. We're like boxers. We just look for the right spots."

The worst body blow came in the second half with a 21-3 run. The knockout punch came when Arenas and Gardner caught the Spartans off guard by cheating for a 67-52 lead.

Andy Katz is a senior writer at ESPN.com.