Penn State was on a pretty good roll until it ran into Iowa's zone defense.
The Hawkeyes, behind the triple-double of Samantha Logic and 24 points from freshman Ally Disterhoft, snapped the ninth-ranked Lady Lions' six-game winning streak, 73-70 on Thursday night.
"Iowa did a good job of packing into the paint and making us shoot jump shots," said Ariel Edwards, who had 16 points for Penn State.
Logic had 14 points, 10 rebounds and 10 assists for her second triple-double of the season and the only two in the Big Ten this season.
"They did a really good job of attacking and getting into the paint," Penn State coach Coquese Washington said. "They did a good job of finding shooters and cutters and they did a much better job of scoring in transition than they did that first game."
At least half of Logic's 10 assists found teammates open and heading for the basket, and Washington called Disterhoft a "tough matchup."
Penn State (17-5, 8-2 Big Ten) beat then-No. 22 Iowa 87-71 on Jan. 5.
"Samantha Logic is a triple-double waiting to happen every single night," said Lisa Bluder, who tied former Iowa coach Vivian Stringer for most career wins at the school with 269.
"It's unbelievable having a point guard like that who can contribute in so many ways. Not just assists, not just scoring, but steals (3).
"And for Ally Disterhoft as a freshman to come in here and go 8 for 9 and be perfect from 3-point (3 for 3) and the foul line (5 for 5), including hitting two fouls with eight seconds left, also was an amazing performance."
Iowa (18-6, 6-4) got 13 points from Melissa Dixon and 10 from Theairra Taylor as the Hawkeyes won their fourth straight Big Ten road game.
Maggie Lucas had 21 points for Penn State, which had won 12 of its last 13 games.
The Lady Lions scored two points in the final 4 minutes after tying the game at 68.
Taylor's jumper put the Hawkeyes up by one but Edwards hit a short jumper for a 70-69 lead.
Bethany Doolittle, who was held to eight points, six below her average, hit a jumper to put Iowa ahead. Edwards, Kaliyah Mitchell and Lucas all missed jumpers and Logic pulled down the rebound. Disterhoft made two free throws for the final margin.
"This is just a really big win for us," Bluder said. "This is our fourth Big Ten road win in a row. That's hard to accomplish. And to come into a No. 9 in the country and beat them on their home court is another whole task."
Despite missing five first-half layups and allowing Penn State to recover from an eight-point second-half deficit, Iowa's 50 percent shooting never allowed the Hawkeyes to stay close.
Iowa maintained its composure each time Penn State made a run, according to Bluder.
"It wasn't the fact that Penn State was a ranked team," she said. "It was that we wanted to really win. We wanted that feeling again. Our team felt very good about coming into this game and that may sound weird after a loss (to Nebraska on Feb. 1), but that loss really motivated us.
"We were going to focus on getting ourselves better and getting our swag back, and I thought we did that tonight."