The Wildcats (5-0 Big Ten, 7-1 overall) won their 13th straight Big Ten game over two seasons, a come-from-behind victory that all but guaranteed a second straight bowl bid for the defending conference champions.
Northwestern has won seven straight and the last four have all been decided in the final minutes - victories over Michigan, Minnesota, Wisconsin and now the Illini.
The Wildcats have won those four games by a total of 10 points.
Adrian Autry finished with 128 yards on 30 carries, starting for Darnell Autry, the school's career rushing leader, who injured his shoulder last week against Wisconsin. The two are not related.
Joe Jurevicius scored one touchdown on a 57-yard reception and set up three other touchdowns with big catches in the second half as the 17th-ranked Nittany Lions beat Indiana, 48-26.
All four receptions by Jurevicius were on passes by backup Mike McQueary, who also had a 55-yard TD pass to Jurevicius against the Hoosiers last year.
Indiana (0-5, 2-6) dominated the first half on the ground and led, 20-10, at the break. But the Nittany Lions (3-2, 7-2) stopped the Hoosiers cold the rest of the way and scored more than twice as many points in the second half as in their first four conference games combined.
The loss was Indiana's 13th straight in the Big Ten over two seasons.
The Buckeyes (4-0, 7-0) spotted Iowa (3-1, 5-2) an early field goal, tied it with one of their own and then scored three touchdowns during an error-filled, five-minute span to grab a big lead for the second straight year.
A year ago, the Buckeyes held a 56-0 halftime lead. On Saturday, it was 31-6 as the Hawkeyes, who shared the conference lead with Ohio State in turnover margin, had four passes intercepted, a punt blocked for a touchdown and a kickoff botched, all in the second quarter.
Sedrick Shaw also fumbled on Iowa's first possession of the second half and the Buckeyes took advantage, with Pepe Pearson bulling in from the four to expand Ohio State's lead to 38-6.