College football rankings: ESPN crowns new No. 1 team in FPI Power Index after Week 9

College football never stays predictable for long, and that's part of what makes every Saturday so much fun. 

One weekend can flip the national picture upside down, send a contender tumbling and give another team a chance to grab the spotlight. Week 9 delivered lots of movement in ESPN's latest Football Power Index rankings. As the season gets deeper, these games tend to feel even more important, too.

The biggest change came at the top, where Notre Dame moved into the No. 1 spot. Ohio State, meanwhile, dropped to No. 2 after its surprising loss to USC. So, it's easy to say that the most significant move this week is getting a brand-new No. 1 team in Notre Dame.

Notre Dame Takes Over No. 1

Notre Dame moved up one spot after improving to 7-1 with a win over Navy. The Irish had to work through a challenging start before putting together 28 unanswered points to pull away. Now, a much bigger test is on the way. Notre Dame faces undefeated Miami in a matchup that could have serious consequences for its playoff chances. Yes, Miami has a perfect record going into this game. The Irish already have a loss to BYU in their column, so another fall would make their path quite a bit tougher.

Ohio State fell to No. 2 after losing to USC, with Julian Sayin's absence proving extra costly. The Buckeyes also couldn't get enough stops defensively when the game was on the line. Next up is Oregon, which visits Columbus with Ohio State's playoff hopes suddenly under pressure. November is arriving with very little room for mistakes.

ESPN FPI Rankings after Week 9

1. Notre Dame
2. Ohio State
3. Miami
4. Georgia
5. LSU
6. Alabama
7. Texas
8. Indiana
9. Ole Miss
10. Utah
11. Wake Forest
12. Oregon
13. Texas Tech
14. Tennessee
15. USC
16. BYU
17. Nebraska
18. Louisville
19. Missouri
20. Houston
21. Iowa
22. Florida
23. Texas A&M
24. Northwestern
25. South Carolina