Iowa was down 23-14 heading into the fourth quarter. But Greene scored his second TD, from 6 yards out, to make it 23-21 with 9:20 left.
On the next possession, Penn State looked as if it got a break, when Iowa was called for a roughing the punter penalty that had the Hawkeyes seething. The Nittany Lions kept the ball and continued its time-consuming march.
But Clark made an errant throw down the middle that was picked off by Tyler Sash, who returned to Iowa’s 29 with 3:46 left. Iowa then caught another break when Penn State was flagged for pass interference on third down, getting the Hawkeyes near midfield with a first down.
Stanzi, who was 15-of-25 passing for 171 yards, hit Derrell Johnson-Koulianos at the Penn State 15 with 18 seconds left to set up Murray’s kick.
“I want to apologize to the whole Penn State nation for my game play today,” Clark said. “I just keep having that turnover recurring in my head over and over. I can’t get it out of my mind.”
This was the biggest win for Iowa in years, its first against a top-five team since 1990. The Hawkeyes suffered through two seasons of mediocrity after finishing No. 8 in the country three years in a row.
The Hawkeyes had lost four games this season by a total of 12 points — and they got beat last week by Illinois on a 46-yard field goal with 24 seconds left.
“We knew we had enough to win,” Iowa linebacker A.J. Edds. “But there weren’t a whole lot of people on the outside that thought we were the kind of team we know we are. We showed that today.”
Clark was 9-of-23 for 86 yards and Derrick Williams and Evan Royster each ran for touchdowns to lead Penn State (9-1, 5-1), which had to settle for Kevin Kelly’s field goals on three different trips inside Iowa’s 20.