IOWA CITY, Iowa (AP) -- Maggie Lucas seemed to hit a big shot every time Penn State needed it.
Lucas scored 21 points and delivered in the second half during Iowa's short-lived comeback attempt to lead the No. 8 Lady Lions to an 81-69 win over Iowa on Thursday night.
Penn State (21-3, 11-1 Big Ten) has won 15 of its last 16 games. The Lady Lions are off to their best conference start since 2003. The only misstep was a two-point loss at Wisconsin two weeks ago.
''Winning on the road in the Big Ten is pretty tough,'' Penn State coach Coquese Washington said. ''It's all about our competitive nature.''
Morgan Johnson had 17 points and 11 rebounds for Iowa (16-10, 5-7) in tying a school record with her 121st career start.
The Hawkeyes have lost five straight, but this was their first loss to a ranked opponent in seven games. The six wins against ranked teams are the most in the nation.
Iowa hit only one field goal during a nearly eight-minute stretch in the second half as their 38-37 lead turned into a 12-pont deficit.
Penn State went on a 19-4 run during that stretch to take control of the game.
Lucas hit a pretty step-back jumper with 12 minutes left to push Penn State's lead to double digits for the first time.
Iowa finally shook its shooting slump, but Lucas and the Lady Lions always had an answer.
After the Hawkeyes hit a pair of free throws for their first points in 4 1/2 minutes, Lucas knocked down a 3-pointer on the other end.
Theairra Taylor's layup gave Iowa only its second field goal in nearly eight minutes, but Lucas responded with a tough drive of her own, earning and converting two free throws.
Penn State hit 52 percent of its shots in the second half thanks to the tough defense.
''When you can get layups in transition and uncontested shots, that helps your offense,'' Washington said. ''Offensively in the first half we weren't quite clicking. In the second half, I thought we got some free throws, some points in the paint and some transition baskets. That got things going for us.''
Penn State's Ariel Edwards scored 15 points off the bench and Alex Bentley added 14 points.
The Hawkeyes desperately needed a win, but some of their strengths failed them against Penn State.
The Hawkeyes lead the Big Ten in free-throw percentage, but made only 11 of 19 against Penn State. They also missed on the front-end of a pair of one-and-ones in the first half.
''The downfall was our free throws,'' Iowa coach Lisa Bluder said. ''That could have kept the game so much closer.''
Iowa's Jamie Printy, who averages 14 points a game, missed all five of her field goal attempts, finishing with two points in 29 minutes.
Reserve guard Melissa Dixon scored 16 points for Iowa, shooting 4 of 9 on 3-pointers.
Both teams looked tight in a sloppy first half that produced 22 turnovers and 20 fouls.
Neither team could pull away early - there were seven ties and eight lead changes in the first half. When Penn State went on a 12-5 run midway through the period to take control, the Hawkeyes responded with a 9-2 burst to close the lead.
Iowa had an opportunity to tie it before halftime, but a blown layup turned into an open transition 3-pointer from Lucas that gave the Lady Lions a 37-34 lead at the break.
The first two rounds of the NCAA tournament will be played at Carver-Hawkeye Arena, but Iowa needs to snap out of its funk if it hopes to enjoy playing on its home court.
The Hawkeyes have quality wins on their resume, but upcoming games at No. 18 Purdue and Nebraska will be critical.
''When you've lost five in a row it's really tough,'' Bluder said. ''We go on the road now with two games and we really need to win one of them.''