IOWA CITY – It seems to happen to every big-name program at least once a season.

Some upstart team with no reputation that is given no chance of winning comes into the big arena and does almost nothing wrong. It opens an early lead and tests the mettle and maturity of the big-name team.

It happened to the Iowa Hawkeyes on Sunday. They passed the test.

The Hawkeyes trailed a spunky Nebraska-Omaha club for about 25 minutes before calmly flicking aside the upstart Mavericks in the last 10 minutes to claim an 83-75 victory at Carver-Hawkeye Arena.

Aaron White collected 20 points and a career-high 15 rebounds as the Hawkeyes also got significant contributions down the stretch from Devyn Marble, Anthony Clemmons, Melsahn Basabe and Jarrod Uthoff to improve their record to 2-0.

“These teams are hard to play against even though you are supposed to win,’’ said Marble, who scored 15 points despite shooting just 2 for 13 from the field. “They come out with nothing to lose, get good guard play, they’re knocking shots down. When guys are doing that they can beat teams on any given night.’’

Iowa coach Fran McCaffery said that in some previous seasons the Hawkeyes have lost similar games. He cited a loss to South Dakota State in his very first game as the Iowa coach in 2010-11 and a home loss to Campbell in 2011-12.

He said it’s a sign of maturity that this year’s team shrugged off the upset bid and ultimately prevailed.

“I’m not saying we’re going to win every game like this, but we did what we had to to win this game,’’ McCaffery said.

McCaffery gave much of the credit to White, a 6-foot-9 junior who never flinched, even when UNO broke out to a 43-36 halftime lead.

“I think the most impressive thing to me is just his understanding of what was needed in a difficult game,’’ McCaffery said. “We played a team that had a terrific game plan. They executed it to perfection. I think they showed everybody what they were made of.’’

White agreed with McCaffery’s assertion that Iowa might have lost this game in some previous seasons.

“Balls weren’t bouncing our way and we weren’t making shots. We weren’t playing the way we wanted to,’’ he said. “But none of us really got down on ourselves, none of us panicked. That’s a testament to a mature team and a team that’s capable of handling a lot of challenges thrown at us. Tonight was a challenge and we handled it.’’

The Hawkeyes actually trailed for about 25 minutes as UNO’s quick backcourt trio of CJ Carter, Justin Simmons and Devin Patterson continually shredded them with dribble penetration and outside shots.

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Iowa finally regained the lead with 9 minutes, 12 seconds to go in the game when Marble got a steal and slipped it to Clemmons for a layup that gave the Hawkeyes a 62-61 lead.

Carter, who led both teams with 22 points, briefly put the Mavericks back on top with a running 10-footer in the lane and he later tied the score at 66-66 with a 3-pointer, but the Hawkeyes gradually took control after that.

A Clemmons 3-pointer put them ahead to stay, kicking off a 14-3 scoring run that made it 80-69 with 1:53 remaining.

“It just comes with learning with each game and each year,’’ Marble said of the comeback. “Even though it’s not a significant win, it could have been a significant loss.’’

Zach McCabe added 12 points for Iowa with Clemmons netting 11 while playing the last 15 minutes of the game without a break.

The Hawkeyes had seven fewer field goals and five fewer 3-pointers than the Mavericks (1-1), but more than made up for it by going 38 for 49 at the foul line.

“I don’t think we guarded the bounce very well,’’ UNO coach Derrin Hansen said. “They ended up getting to the foul line a lot more than we did.’’