The reigning champs stood at No. 3 in each of the previous CFP rankings this season, but a heartbreaking loss to Michigan State (which rose to No. 5 this week) sent the Buckeyes spiraling down to No. 8.
A three-point win over a three-win Boston College team wasn't good enough in the committee's eyes for the Fighting Irish to stay in the top four, and they settled in at No. 6.
With wins this weekend, Iowa and Michigan State would meet in the Big Ten championship game in what would amount to a CFP play-in game.
Another matchup that could lead to a CFP shakeup is the Bedlam game between Oklahoma and No. 11 Oklahoma State. The Cowboys tumbled five spots after losing to Big 12 rival Baylor for their first loss of the season. The victory pushed the Bears up from No. 10 to No. 7 in this week's poll. Although Oklahoma State fell out of the top 10 this week, a win over the archrival Sooners could serve as a shot in the arm while dashing any hopes Oklahoma has of vying for the national title.
While the Big 12 is filled with CFP possibilities, the SEC is taking some hits. At No. 12, Florida is the second-highest ranked school from the conference, behind No. 2 Alabama. There are only two other entries from the SEC in this week's rankings with in-state foes Ole Miss at No. 18 and Mississippi State at No. 21.
The ACC has back-to-back entries with Florida State moving up one spot to No. 13 and North Carolina climbing three notches to No. 14. The Tar Heels, winners of 10 straight, can make a huge statement in two weeks if they can knock off top-ranked Clemson in Charlotte.
At No. 15, Navy remains the highest-ranked team from outside the Power 5 conferences. Following the Midshipmen and rounding out the top 20 are Northwestern, Oregon, Ole Miss, TCU and Washington State.
Houston, which had been in the running with Navy as the best team from a Group of 5 conference, fell from No. 19 to completely out of the rankings after UConn dealt the Cougars their first defeat of the season.
The committee of 12 people was operating with just 11 this week as member Mike Tranghese was under the weather, according to CFP chairman Jeff Long.