Iowa moved to No. 3 in The Associated Press college football poll, taking advantage of the first losses by Ohio State and Oklahoma State to slip in behind No. 1 Clemson and No. 2 Alabama.
Notre Dame is fourth and Oklahoma is fifth.
The unbeaten Hawkeyes (11-0) have their best ranking since being No. 3 in 2002. They have clinched the Big Ten West and a spot in the conference title on Dec. 5.
Michigan State jumped three spots to No. 6 after upsetting Ohio State 17-14 on Saturday. The Buckeyes, who began the season as a unanimous No. 1 and slipped to No. 2 earlier this month, fell to eighth.
Oklahoma State's 45-35 loss to Baylor dropped the Cowboys from fourth to ninth and pushed Baylor to seventh.