Denard Robinson played after missing two-plus games with nerve damage in his right elbow. Robinson started at running back and took some snaps at QB, but he didn't throw a pass.
Michigan running back Fitzgerald Toussaint appeared to break his left leg on his team's first drive.
The Wolverines didn't need Toussaint to beat Iowa, but it will be more difficult to beat Ohio State for a second straight year without him next week.
It looked as if Toussaint's left leg snapped between his ankle and knee on his third carry when he was tackled by two Hawkeyes after getting an option pitch from Robinson on Michigan's first drive. Toussaint was carted off the field with his left leg in a brace.
The Wolverines did what they wanted through the air and on the ground against the Hawkeyes.
Gardner was 18 of 23 for 314 yards with TD passes to Roy Roundtree, Vincent Smith and Devin Funchess. Gardner ran for 37 yards, scoring on three short runs to lead a barrage of points that finally ended late in the third quarter.
Robinson ran 13 times for 98 yards, including a 40-yard sprint that included quite a juke along the sideline in the senior's last home game.