Iowa’s 12-point lead almost midway through the third quarter narrowed as slim as three with 9:05 left in the fourth. Ohio State’s Cotie McMahon scored five of her 21 points in the final frame, but Czinano went 3 for 3 in the fourth quarter to help keep the Buckeyes at bay.
The Hawkeyes (16-4, 8-1 Big Ten) kept Ohio State scoreless for more than 2 1/2 minutes in the fourth quarter, allowing Czinano and Iowa to command a 13-point advantage with 3:11 remaining.
Ohio State (19-1, 8-1) gave one more try and went 4 of 9 from the field in the final three minutes, but the Hawkeyes made all eight attempts at the free throw line to seal the win.
Despite trailing 24-23 after Ohio State's Taylor Mikesell made a buzzer-beating 3 at the end of the first quarter, Clark and the Hawkeyes caught fire in the second.
Iowa went on a 9-0 run just over one minute into the second quarter, led by Clark who scored seven of those points after notching five in the first frame, and flipped the lead 32-26.
Czinano led all scorers at halftime behind 14 points. She picked up her fourth foul of the game in the third quarter, and the Buckeyes tried for a comeback bid.
Ohio State shot 38%, its worst in five games, and 16% from 3-point range, its lowest mark of the season. Taylor Thierry scored 20 points and had nine rebounds.
Iowa: Turnovers remained an issue for the No. 2 scoring offense in the NCAA even after the Hawkeyes gave it away a season-high 20 times last time out against Michigan State in overtime Wednesday. Iowa had 17 giveaways against Ohio State’s press defense, including 11 in the second half.
Ohio State: The 19-game, season-opening win streak came to a close. The Buckeyes entered 4-0 against Top 25 opponents this season, and the challenge won’t slow as their next matchup will be with a top 10 conference foe.
Iowa: Hosts Nebraska on Saturday.
Ohio State: Travels to No. 6 Indiana on Thursday.