Iowa improved to 4-1 all-time in OSU's palatial home of six seasons with a 78-67 win before 13,949 Wednesday night.
The Hawkeyes (14-9, 7-5) rode hot shooting to a win that moved them into sole possession of fourth place in the Big Ten. Iowa hit 56.3 percent from the floor (27 of 48), including a blistering 9 of 15 (60 percent) from behind the three-point arc.
"Our biggest problem continues to be our inability to defend," said OSU coach Jim O'Brien. "We keep preaching the same song. Unless we make a commitment to guard a little better, we need to shoot in the 60s ourselves to overcome it."
Brody Boyd connected on 6 of 9 three-point tries in posting a career- and game-high 25 points. Pierre Pierce added 19 points, while Glenn Worley and Jeff Horner each had 12.
"We got in here this morning and I got a lot of shots up," Boyd said. "That helped with my confidence. I was feeling comfortable shooting the ball. Any time you get the ball and feel that way, you're going to shoot well."
In the first meeting with OSU, Iowa's three-man backcourt of Horner, Boyd and Pierce combined for 54 points in a 79-65 win. They outdid themselves this time around, combining for 56 points.
"Once again, their guards had their way with us," O'Brien said.
Ohio State (11-13, 3-8) lost its third straight game and likely saw its hopes of prolonging its five-year string of postseason play go by the boards. OSU would likely need a 4-1 finish to the regular season to assure itself of an NIT bid.
"They are all frustrating losses," said OSU center and captain Velimir Radinovic, who had 16 points, nine rebounds and hit 7 of 8 shots from the floor. "One doesn't hurt any more than any other. I hate losing, especially at home. It's frustrating that we can't get it done."
Tony Stockman had 16 points as well. But Stockman was just 6 of 17 from the floor. Terence Dials chipped in 14 points and five assists, while Ivan Harris had 11 points and seven rebounds in just 17 minutes of work.
The first half was almost shades of OSU's loss to Michigan State, where the Spartans shot 81 percent from the floor in the first half. Iowa made 9 of its first 11 shots on its way to a 62.1 percent half (18 of 29). Particularly hot was Pierce, who made 7 of his 9 first-half shots on his way to a 14-point half.
"He's very hard to defend off the dribble," Iowa coach Steve Alford said of Pierce, who routinely slipped away from OSU's J.J. Sullinger in the opening minutes. "Pierre is one of those guys you have always got to be conscious of because he can always take you off the dribble."
OSU trailed 14-11 after Radinovic completed a three-point play with 15:10 left in the first half. Iowa then outscored OSU 14-8 over the next five minutes as Boyd and Worley each hit three-pointers and Horner completed an alley oop in transition to Erek Hanson. That play put Iowa up 28-19 with 10:31 left in the half.
Ohio State then reeled off the next nine points, including five from Stockman, to tie the game at 28-28 with seven minutes left. The Buckeyes trailed 38-36 after Stockman hit a baseline jumper with 2:35 left in the half.
That was when the Buckeyes experienced another late first-half implosion, allowing Iowa to score the last six points of the half and go up 44-36 at the intermission. The capper was Greg Brunner's two-hand jam in transition with 36 seconds left. OSU held for a final shot, but Brandon Fuss-Cheatham's 6-foot jumper was easily blocked by Hansen before the buzzer.
"I thought we took a couple quick shots and had a couple turnovers at the end of the half," O'Brien said. "It was similar to what happened at Wisconsin (Saturday). We turned a two- or three-point game into eight points at the half. That puts you behind the eight ball. We were just fighting uphill after that."
Iowa twice grabbed a 13-point lead early in the second half. The first time was on a Boyd three-pointer to make it 49-36 with 18:20 left. The second time came on a Worley three-point play to make it 54-41 with 13:31 left.
OSU then used a 10-4 run, capped by Harris' baseline jumper, to cut the Iowa lead down to 58-51 with 9:53 left. But the Hawkeyes answered with a 9-2 run, keyed by a Boyd three-pointer and back door layup, to go back up 14 at 67-53 with 4:34 left.
The loss drops OSU's home record to 8-6. OSU now embarks on a three-game road trip, beginning at Indiana Saturday (8 p.m., ESPN-Plus).
O'Brien bristled when asked how he would get his team back up for the three-game road stretch, which also includes trips to Minnesota and Michigan.
"That's all part of the deal," he said. "We don't look at it as three games. Our next game is at Indiana. Hopefully our guys will be ready to play. Our challenge as coaches will be to get them up. Hopefully they will have some interest on their own to get up. We can't do it all for them.
"We will have practice tomorrow at 1:30 and we'll get back after it tomorrow. We're not going to take any time off. They better be in the gym tomorrow at 1:30."