Tarvis Williams goes up for the winning shot as Hampton pulls off the biggest upset of the day. (AP)

"Marseilles and I made eye contact and he made a good pass into me underneath," said Williams, who had four fouls for much of the second half. "When I'm underneath, I feel confident with my touch and my jump shot, and I just concentrated on that."

Iowa State's Jamaal Tinsley took the ball downcourt but missed a layup with 1.2 seconds to go, setting off a midcourt frenzy as the Pirates, their band, their cheerleaders and their fans swarmed the floor in celebration.

David Johnson carried coach Steve Merfeld halfway around the court as Merfeld furiously pumped his fists.

The Cyclones (25-6), who came within one game of the Final Four last season, left the court in shock. Before this game, Iowa State lost to Baylor in the semifinals of the Big 12 tournament.

"It doesn't matter that we lost to Baylor and Hampton at the end," Eustachy said. "This was one of the best teams ever in Iowa. It just didn't go well at the end."

But the Cyclones were outscored 14-2 in the final eight minutes, getting nothing after Martin Rancik's bucket gave Iowa State a 57-48 lead with 7:01 remaining.

"It's just devastating to go out like this," Iowa State's Kantrail Horton said.

Hampton advanced to play Georgetown, which beat Arkansas 61-60 on another late basket.

"It was a great win. I thought our kid persevered," Merfeld said. "They took control of the game, but we just hung in there and hung in there ... Tarvis played with four fouls the last 12 minutes, and it's fitting he got the game winner."

Asked what he thought about Georgetown, he said: "I didn't know anything about them."

The Pirates trailed by as many as 11 points in the second half but pulled to 57-54 with 2:53 remaining on a basket by Isaac Jefferson, then forced a turnover at the other end.

It was 57-56 with 1:44 to go when Brown split the lane for a layup, capping a fastbreak that started when Williams blocked a shot by Iowa State's Rancik.

Eustachy got his first head coaching job at Idaho from 1990-93, and he couldn't have felt too welcome when the Boise fans cheered for Hampton most of the night.

The Mid-Eastern Athletic Conference champion Pirates were making their first NCAA Tournament appearance. Until now, Hampton wasn't known for much other than being the school that produced NBA tough guy Rick Mahorn.

You can bet everyone back in Iowa, from Council Bluffs to Davenport, knows more about the Pirates now.

"They played a good game. They guarded me tough. But I just couldn't make my shots," said Tinsley, who shot 4-of-11.

The Cyclones didn't start like the team that reeled off winning streaks of 10, eight and seven games and won the Big 12's regular-season title. They came out listless, shooting 9-of-27, and trailed 31-27 at halftime.

Things stabilized early in the second half, as the Cyclones using a 9-0 run to erase Hampton's lead. Iowa State led 46-35 after a 19-4 run through the midpoint of the second half.

But Hampton pulled within 48-43 on a jumper by Tommy Adams with 10:33 to play and 50-44 after Williams made one of two free throws. Tinsley made a 3-pointer and Shane Power got free for a dunk to give the Cyclones a 55-44 lead.

Hampton had two transfers with NCAA Tournament experience.

LaSean Howard was part of Syracuse's run to the round of 16 in 1998 and Brown played the point for Richmond the same year when the 14th-seeded Spiders stunned third-seeded South Carolina.