Iowa and Clemson dropped out of the undefeated ranks Saturday, leaving DePaul as the only Division I school with a perfect record in college basketball.
Iowa, ranked No. 1, was stunned by Ohio State, 80-76, at Iowa City. Clemson, ranked 10th, was knocked off by 12th-ranked Duke, 105-103, in overtime at Clemson, S.C.
Iowa had defeated three Top Ten teams--Indiana, Purdue and Illinois--in the last nine days.
Dennis Hopson scored 36 points for the Buckeyes, who took advantage of poor free-throw shooting by the Hawkeyes in the final three minutes.
Hopson was 12 of 21 from the floor, hitting one of four from three-point range. He shot 11 of 13 free throws.
Iowa (18-1, 6-1) dropped into a tie with Indiana and Purdue for the Big Ten lead. Ohio State is 13-6, 4-3.
Iowa out-rebounded Ohio State, 44-26, but the Hawkeyes shot only 43% from the free-throw line, while the Buckeyes shot 70%.
"We played pretty well, coming off a streak of very, very fine performances," said Tom Davis, first-year coach of the Hawkeyes. "We were just flat-out beat today. Ohio State ranks right up there with teams like Illinois and the rest of them.
"I've told people before, we've got our hands full every time we step out onto the floor in any game in this conference."
Ohio State Coach Gary Williams, also in his first season, was an assistant to Davis at Lafayette College and Boston College. It was their first meeting as head coaches.
"Out of respect for Iowa's defense, we probably worked harder against the press than any other team I've coached against in my career," Williams said.
Iowa usually relies on defensive pressure to produce turnovers and easy baskets. The Hawkeye press produced only seven turnovers. Iowa turned the ball over 14 times.
At Clemson, the Blue Devils' Danny Ferry sank a baseline jumper with 77 seconds left and blocked a last-second shot by Clemson, who blew a nine-point lead in the last four minutes.
Duke improved to 14-3 overall and 4-2 in the Atlantic Coast Conference. Clemson fell to 17-1 and 4-1.
Clemson led, 83-74, before Duke began hitting from three-point range. The Blue Devils connected on four three-pointers in the next three minutes, with Tommy Amaker's three-point jumper tying the game, 92-92, with 15 seconds remaining to send it into overtime.
John Smith, who scored 8 of Duke's 13 overtime points, led the Blue Devils with 28 points. Ferry and Kevin Strickland added 18 each, and Amaker had 17.
Clemson was led by Horace Grant with 33 points, followed by Jerry Pryor with 21.
DePaul, ranked No. 6, meets No. 15-ranked Georgetown today in a nationally televised game at Landover, Md. Last season, after winning its first six games, DePaul was beaten at home by Georgetown, 85-70.
Indiana 77, Minnesota 53--Steve Alford hit only 7 of 16 shots but wound up with 24 points, including 10 straight in a 21-2 first-half spurt that put the No. 3-ranked Hoosiers in command at Minneapolis.
Indiana is 15-2, 6-1; Minnesota 9-8, 2-5.
Alford raised his career total to 2,064 points, moving past Mike Woodson's 2,061 for second place on Indiana's all-time list and eighth in Big Ten history.
Indiana's Rick Calloway hit 8 of 8 shots and scored 17 points.
North Caorlina 92, Georgia Tech 55--J.R. Reid and Jeff Lebo each had 15 points for the No. 2-ranked Tar Heels, who led, 43-23, at halftime in handing the Yellow Jackets their worst loss of the season, at Chapel Hill, N.C.
North Carolina, which has lost only to UCLA, is 17-1, 6-0. Georgia Tech is 9-7, 1-4.
Georgia Tech's Duane Ferrell, the ACC's second-leading scorer, was held to two points. Tom Hammonds led the Yellow Jackets with 18 points.
Syracuse 64, St. John's 63--St. John's Mark Jackson barely missed a three-pointer with six seconds left, and the No. 7-ranked Orangemen hung on after blowing a 17-point lead in front of 30,529 fans at the Carrier Dome in Syracuse, N.Y.
Syracuse improved to 17-1 overall and 6-0 in the Big East. St. John's, ranked 14th, dropped to 13-3 and 4-3.
Jackson scored the last eight points in a furious comeback by the Redmen, but his final shot bounced off the back of the rim and was bobbled before Syracuse center Rony Seikaly grabbed it.
St. John's Willie Glass led all scorers with 25 points, and Jackson had 14. The Orangemen were led by Sherman Douglas with 16 points.
Villanova 86, Seton Hall 82--Gary Massey scored 5 of his 21 points in the final 1:41 as the Wildcats (11-7, 4-3) edged the Pirates (11-6, 2-6) at Villanova, Pa.
Kenny Wilson had 18 points, and Mark Plansky had 17 for Villanova. Seton Hall was paced by Mark Bryant with 25 points, followed by James Major with 23.
Pittsburgh 80, Boston College 62--At Boston, Charles Smith and Jerome Lane each had 18 points for the No. 16-ranked Panthers, who improved to 14-4 and 3-2.
Boston College (8-8, 1-5) got 20 points from Dana Barros, who hit four three-pointers.