STATE COLLEGE, Pa. -- On No. 5 Penn State's first offensive play of the game against Iowa on Saturday night, quarterback Daryll Clark threw a 79-yard touchdown pass to wide receiver Chaz Powell. The Hawkeyes didn't let the Nittany Lions score another one.
On the Nittany Lions' next possession, they generated a 20-play drive to the Iowa 11 and kicked a field goal to take a 10-0 lead. The Hawkeyes didn't let them take another snap inside the Iowa 30.
Whatever offensive weapon Penn State used against Iowa, the Hawkeyes wrested away. Hawkeyes? Iowa's defenders morphed into boa constrictors. They methodically, patiently, inexorably wrapped themselves around Penn State's offense and squeezed its lungs free of air.
By the fourth quarter, the Spread HD could transmit very few yards, much less points. In the final 15 minutes, the Hawkeyes converted a blocked punt and three turnovers into 16 points and a 21-10 victory.
Unranked, unappreciated Iowa, three weeks after needing a miracle to defeat Northern Iowa, is 4-0 and giving notice that the Big Ten champion will have to go through Iowa City.
Hawkeyes coach Kirk Ferentz used the word "resilient" to describe his team at least three times in his postgame news conference.
"There was nothing easy out there," Ferentz said.
Penn State wanted revenge after a 24-23 loss last season that prevented the Nittany Lions from playing for the national championship. Clark, who tried to shoulder the blame for that loss single-handedly, had taped a derogatory e-mail that he received afterward in his locker for motivation during the offseason.
Instead of revenge, the Nittany Lions got reprise. Just like last year (cold, wind), the weather stunk (rain). Just like last year, Penn State jumped out to an early lead, only to crumple under Iowa's relentless defensive pressure.
Just like last year, Clark finished with poor numbers (12-for-32, three interceptions, 198 yards). And just like last year, just like seven of the past eight games in this Big Ten rivalry, Iowa won.
"We're not a big blitz outfit," Ferentz said. "Our best defenses are when we generate energy up front."
That is where this game, played in front of 109,316 sodden fans, turned. Penn State's offensive line is inexperienced. Iowa ends Adrian Clayborn and Broderick Binns and tackles Karl Klug and Christian Ballard dominated the line.
Binns had a hand in two sacks of Clark, including one that resulted in a second-quarter safety that put Iowa on the scoreboard. Binns bull-rushed right tackle DeOn'tae Pannell so effectively that he not only forced the safety but also got Pannell benched. Then Binns went to work on Pannell's backup, Nerraw McCormack.
"It's real fun just knowing that the game is on our shoulders," Binns said. "It lets us know we are valuable to this team. It feels really good knowing that at any point in time we can stop them."
The Nittany Lions had 147 yards of offense on their first two possessions but minus-6 yards the rest of the half. Yet their defense kept Penn State ahead. In the first half alone, Iowa crossed midfield five times but never entered the red zone. The Hawkeyes had three points to show for their travels.
The score remained 10-5 into the fourth quarter, when Clayborn single-handedly changed the game with the blocked punt. The junior blew through Penn State safety Nick Sukay, blocked Jeremy Boone's kick, picked it up on the second bounce and returned it 53 yards for the Hawkeyes' first touchdown and first lead, 11-10, with 12:21 left to play. Clayborn managed to inflate his teammates and deflate the Nittany Lions all at once.
"I was running around and screaming like a little girl trying to catch him," said Iowa linebacker Pat Angerer, who finished with 14 tackles and two turnovers. He intercepted Clark on Penn State's ensuing possession and returned it 38 yards to the Nittany Lions' 24. Three plays later, Adam Robinson ran for a 13-yard touchdown, and the Hawkeyes pulled away.
Ferentz, whose public temperature never rises above simmer, acknowledged that expectations are about to rise. The Hawkeyes no longer will be unranked.
"That will be the next challenge," Ferentz said, chuckling to himself. "That's coming. That's human nature. How can you handle a little success? I've always thought that's tougher than handling adversity."
Paterno tinged his postgame comments with equanimity. He talked about his team's inexperience, especially on the offensive line.
"I think it's a question of learning and not feeling that all is lost," Paterno said. "I think we can learn from it and get better."
Iowa must play at Wisconsin and at Ohio State. The Hawkeyes don't get to play Purdue or Illinois, who look to be two of the league's lesser lights. But the Hawkeyes' road to the Big Ten championship looks shorter than it used to.
Ivan Maisel is a senior writer for ESPN.com. Send your questions and comments to Ivan at Ivan.Maisel@ESPN3.com.