IOWA CITY — Iowa freshman Keith Duncan gave Michigan’s hopes for an unbeaten football season a swift kick Saturday night.

The Hawkeye walk-on split the uprights with a 33-yard field goal as time expired, stunning the second-ranked Wolverines 14-13 and sending thousands of fans onto the field at sold-out Kinnick Stadium for a raucous postgame celebration.

“A win is a win, anyway you can get it and Keith Duncan did a great job hitting that field goal. I saw it go through, I threw up my hands and stormed the field with everybody else,’’ quarterback C.J. Beathard said. “We came out ready to go today, fought the entire day and came out with a win.’’

The victory, making Iowa bowl eligible and taking some of the sting off of back-to-back losses to rated opponents, came less than two minutes after Michigan’s Channing Stribbling intercepted a Beathard pass on the Wolverines’ 16-yard line.

Stribbling’s pick, the only turnover of the night by the Hawkeyes, preceded a Michigan three-and-out crafted by an Iowa defense which limited the Wolverines to 201 total yards, well below the 497.4 yards Michigan averaged on its way to a 9-0 start to the season.

Akrum Wadley, who led Iowa with 116 rushing yards, caught a 10-yard pass to open the Hawkeyes’ game-winning drive. Beathard positioned Duncan for his winning kick, scrambling for eight yards on a third-and-seven draw play to the Michigan 15-yard line.

The Wolverines burned their final timeout to ice Duncan, who has now hit eight of nine field goals this season.

“It was a team effort from start to finish. It had to be there,’’ Iowa cornerback Desmond King said. “You’ve got to have the energy. You’ve got to have the will to fight for each other. We prepared all week and we had to believe that we could do it.’’

Duncan collected all six points Iowa needed to earn its first win over a second-ranked team since beating a Wolverines’ team quarterbacked by Michigan coach Jim Harbaugh 12-10 in 1985.

His first career game-winning effort countered a 51-yard field goal by Michigan’s Kenneth Allen with 9:35 remaining, completing a drive extended by a rare roughing the center call.

The kick erased an 11-10 lead by Iowa, the first time Michigan trailed in the second half of a game during its 9-0 season and something that happened after Iowa capitalized on a Wolverines turnover to open the second half.

Jack Hockaday forced and Brady Ross recovered a Kahlid Hill fumble on the opening kick at the Michigan 35-yard line.

Jerminic Smith gained eight yards on a reverse and Akrum Wadley collected back-to-back gains of 12 yards as the Hawkeyes marched as deep as the four-yard line before a sack and an incompletion brought Duncan into the game for a 25-yard field goal to give Iowa an 11-10 lead, extending a rally the Hawkeyes began midway through the second quarter.

Iowa scored the final eight points of the opening half, cutting into a 10-0 lead the Wolverines had opened.

“Momentum changed right before the half,’’ Beathard said. “We felt from the beginning that we could win it. We knew it would be a battle. If you want to hang with these guys, you have to hang tough.’’

The leg of punter Ron Coluzzi positioned the Hawkeyes for their first points, driving a 54-yard punt to the Michigan two-yard line where Jaleel Johnson chased down running back De'Veon Smith in the end zone for Iowa’s first safety in two seasons.

Beathard, connecting on just two of his first nine pass attempts, warmed up to give the Hawkeyes a chance to tie the game shortly before halftime.

Beathard hit Wadley with consecutive passes of 27 and seven yards to open a seven-play, 52-yard drive that ended when Iowa’s senior quarterback hit Wadley over the middle for a three-yard touchdown on a fourth-down play with 1:27 left in the half.

Trailing 10-8, the Hawkeyes attempted to tie the game on the conversion but Adrian Falconer could not hold onto a well-placed pass from Beathard and Iowa headed to the locker room at the break trailing by two points.

Michigan scored on two of its first three possessions to open an early lead.

The Wolverines used a 26-yard field goal by Allen to collect the only points of the opening quarter, a lead which reached 10-0 when Ty Isaac scored on a seven-yard touchdown run with 8:56 remaining in the second quarter.