ANAHEIM, Calif. - Mike Krzyzewski pulled his two seniors close and raised his voice so he could be heard among the din of thousands of screaming Arizona Wildcats fans.

"He said, 'Keep your heads up. You guys have been champions,'" guard Nolan Smith said. "He was talking about last year."

Then, with 1 minute 59 seconds remaining in a 17-point game, Duke's legendary coach pulled Smith and forward Kyle Singler out of the game. There was no point in keeping them on the floor in a blowout.

Arizona stunned the defending NCAA champions 93-77 in Thursday's night's regional semifinals at the Honda Center, blitzing them so badly in the second half that many Blue Devils may still not know exactly what went wrong.

It's simple: Duke got Duked - run off the floor by a team that hit every big shot and grabbed every important rebound.

It was a strange, sinking feeling for a top-seeded team that had won games by 46, 42, 37 and 32 points this season. Arizona outscored Duke 55-33 in the second half, and out-rebounded it 25-9. The UA pulled even - and then ahead - with a 19-2 run midway through the second half.

Guard Kyrie Irving, who came off the bench to score a team-high 28 points, said he could count on one hand the number of times his team has been blitzed after holding a halftime lead.

Singler said he's been thumped in a half like that before.

"But it doesn't happen often," he said.

Challenged to pull out of a tailspin, the Blue Devils seemingly froze. A team known for its smarts panicked. The energy that boosted them to a six-point first-half lead disappeared in a SoCal haze.

"I can't explain that," Krzyzewski said. "That's what happens in sports. Sometimes one team gets more aggressive than the other. … Sometimes, when you get on a roll, you have more energy than the other guy who doesn't get on a roll. I think it's something our kids did poorly, but we had no stop for them."

Irving and Singler were stellar offensively, combining for 46 of the team's 77 points. Irving hit 9 of 15 shots, and dished out three assists. Singler scored 18 points and grabbed eight rebounds.

Smith struggled, shooting just 3 of 14 from the field, and finished with eight points and five rebounds.

Arizona simply made more plays - and got more loose balls - than a Duke team that's not used to being bullied.

"It's a little different being in that position," Irving said. "But when a team beats you like that, all you can say is, well, they really deserved it."