CHAMPAIGN, Ill. — That huge gust you felt coming from the southeast wasn’t the latest winter storm front coming through.

It was a collective sigh of relief from the Iowa basketball team.

The Hawkeyes dug themselves a gaping hole on the scoreboard again Thursday night, but staged a frenetic second-half comeback and then dominated in overtime on their way to their first Big Ten victory, a 104-97 conquest of a determined Illinois team at State Farm Arena.

Jordan Bohannon tossed in 29 points and the Hawkeyes got double-doubles from both of their primary post players. Tyler Cook had 21 points and 13 rebounds and freshman Luka Garza collected 19 points and 11 rebounds, including many of the game’s biggest plays in the final 10 minutes.

"It’s huge," Cook admitted after he and his teammates improved to 1-5 in the Big Ten, 10-9 overall. "I felt like we put it all together over the full stretch of the game and into overtime."

Garza said the Hawkeyes were determined not to lose, even after falling behind by as much as 20 points in the first half.

“I think it was just a mindset,’’ he said. “We didn’t want to lose. We weren’t going to lose.’’

Garza scored 13 of his 19 points in the last five minutes of regulation and in overtime as the Hawkeyes showed tremendous resilience. They didn’t even flinch when Illinois freshman Trent Frazier hit a running jumper from just behind the 3-point line to tie the game at the horn ending regulation.

Cook said he looked around at his teammates’ eyes in the huddle prior to the overtime period and knew the game was in hand.

“I said ‘This just gives us a chance to win by 10 instead of just 3,’’’ he said.

The Illini (10-8, 0-5 Big Ten) already had had four players foul out at that point. They never had a chance.

Nicholas Baer started the overtime with a free throw, Cook got a dunk off a feed from Bohannon, Garza notched a 3-point play on a putback, Bohannon drilled his fifth 3-pointer of the game and Maishe Dailey added a free throw to make it 100-90 with a minute, 12 seconds remaining in overtime.

The Hawkeyes managed to hold on from there, much to the chagrin of Illinois coach Brad Underwood, whose team has blown big second-half leads before.

“I don’t know what it is about the second half,’’ Underwood said in a tense postgame news conference. “Got to figure it out, going to figure it out, have to figure it out.’’

The game looked like what it was expected to be: Two teams fighting wildly and desperately to get their first Big Ten win.

In the first half, it looked as though that was going to be the Illini. Instead of going through just one devastating lapse in the first half, as it has in other games, Iowa actually had two and found itself trailing Illinois by as much as 20 (49-29) in the opening 20 minutes.

Illinois reeled off 13 straight points in a run in which Iowa missed seven straight shots and also turned the ball over five times and the Illini later added a 10-0 run to seemingly take control.

However, Bohannon and Cook led a charge that trimmed the margin to 54-41 at halftime.

Iowa coach Fran McCaffery said he didn’t say anything very significant at halftime

“Nothing that smart,’’ he said. “Just stay the course.’’

“It didn’t start in the second half,’’ McCaffery added. “We cut it at the end of the first half. … It was a manageable number at halftime.''

The Hawkeyes immediately got back in the game by scoring the first 10 points of the second half, the last six on a pair of 3s by Baer and Bohannon.

“We came out right from the jump in the second half,’’ Garza said. “We had more intensity than them. They had been kicking our butts in terms of that, outhustling us and stuff like that, and we weren’t going to let it happen anymore.’’

The Illini still were clinging to an 82-79 lead following a 3 by Frazier with 5:21 remaining, but Garza took over the game at that point, scoring eight consecutive points to give the Hawkeyes an 87-82 lead.

Frazier, who led the Illini with 27 points, knocked down another 3 with 1:15 to go. Garza made two free throws with 4.9 seconds left to give the Hawkeyes a 90-87 cushion, but Frazier dribbled up the right side and threw in the tying shot as the horn sounded.

The comeback from a 20-point margin is the second largest ever by an Iowa team on the road. The only larger comeback was a rally from a 22-point margin in a 1987 game in Champaign.

“Looking up at the scoreboard and damn, we were down 19, and we said we’re not going to do this any more …,’’ Garza said. “We’re not going to go 0-6.’’