IOWA CITY, Iowa — The toughest part of Ohio State's schedule is behind the Buckeyes.

And Troy Smith and Co. handled it with ease.

Smith threw for 186 yards and four touchdowns and No. 1 Ohio State picked up its second road win over a ranked opponent by manhandling No. 13 Iowa, 38-17, last night.

Ohio State (5-0, 2-0 Big Ten) faced three ranked teams in September — Texas, Penn State and the Hawkeyes — and beat them all by at least 17 points.

"That's something we talked about, how brutal that September schedule is," Ohio State coach Jim Tressel said. "We've played against some tough teams who brought all they could bring us."

Ohio State, which extended the nation's longest winning streak to 12 games, won't face another team currently ranked until its season finale against Michigan on Nov. 18.

Iowa (4-1, 1-1) fell to 0-10-1 against No. 1 teams and couldn't put up much of a fight in the most anticipated game at Kinnick Stadium in more than 20 years.

"By my vantage point, this is the best they've played all year," Iowa coach Kirk Ferentz said of the Buckeyes. "This wasn't an easy one to walk into as a visitor."

Ohio State broke open a 21-10 game with long scoring drives on its first two possessions of the second half. Anthony Gonzalez stunned the Kinnick crowd with a 30-yard TD catch that put the Buckeyes ahead 28-10.

Ohio State's next drive only netted an Aaron Pettrey field goal. But it ate almost eight minutes off the clock and gave the Buckeyes a 21-point lead heading into the fourth quarter.

The Hawkeyes closed to 31-17 on a 4-yard TD pass by Drew Tate on fourth down. But Ohio State forced a fumble and two interception on Iowa's next three possessions.