Iowa is gearing up for its biggest home game since the 1980s, Cincinnati has its highest ranking in 12 years and Clemson is on the outside looking in at The Associated Press college football poll for the first time since 2014.

Alabama and Georgia are the only constants during this topsy-turvy college football season. They held down the top two spots for a fifth straight week in the AP Top 25.

Alabama received 53 of a possible 62 first-place votes Sunday, with Georgia picking up the rest.

After those two teams, the movement up and down and in and out of the Top 25 was about what would be expected after a week in which nine ranked teams lost, including four in the top 10.

Through the first five weeks of the season, 34 ranked teams have lost, the most in poll history.

Iowa leapfrogged Penn State to take the No. 3 spot after its 51-14 road win over previously unbeaten Maryland. The Hawkeyes have their highest ranking since 2015. Penn State beat Indiana 24-0 at home and remained No. 4.

No. 5 Cincinnati, coming off a 24-13 road win over Notre Dame, has its best ranking since Brian Kelly's 2009 Bearcats were No. 4 in the first week of November.

Oklahoma, Ohio State, Oregon, Michigan and BYU round out the top 10.

Clemson's 19-13 home win over previously unbeaten Boston College didn't impress voters enough to keep the Tigers in the Top 25. Thus ends their streak of 107 consecutive weeks in the rankings. The last time the Tigers were unranked was the week of Oct. 5, 2014.

They are one spot out of the Top 25, 15 points behind San Diego State.

POLL POINTS

Midway through the season, it's strange that a rankings-based debate over the top two teams in the Big Ten doesn't include Ohio State.

The Buckeyes very well may be the best, and the voters certainly show their respect by ranking them ahead of Oregon despite a Week 2 home loss to the Ducks and a meh home win over Tulsa in the following game.

This week's Penn State-Iowa clash is the Big Ten's game of the year -- so far.

It will be the highest-ranked matchup in Iowa City since 1985, when the No. 1 Hawkeyes beat No. 2 Michigan 12-10 on a field goal as time ran out for what Hayden Fry called the biggest win in program history.

IN

• No. 16 Kentucky (5-0) is rewarded for its win over then-No. 10 Florida with its first ranking of the season.

• No. 21 Texas (4-1) beat TCU for its third straight victory and is back in for the first time in a month.

• No. 22 Arizona State Sun (4-1) returns after wins over Colorado and UCLA.

• No. 24 SMU is 5-0 for a third straight season.

• No. 25 San Diego State (4-0) returns for the first time since November 2019.

OUT

• Clemson managed only one touchdown and four field goals against BC. The Tigers get a week off before facing a top-15 defense at Syracuse.

• Texas A&M got bounced for losing two in a row and Alabama comes calling this week.

• Fresno State is out following two weeks after committing six turnovers and blowing a two-touchdown lead in the fourth quarter against Hawaii.

• UCLA was ranked for three straight weeks but got bumped after losing two straight home games.

• Baylor couldn't get its running game going against Oklahoma State and is out after a one-week appearance.

CONFERENCE CALL

Losses by Arkansas and Florida made room for the Big Ten to claim four of the top 10 spots, and Michigan State is sitting at No. 11.

Last week, the Southeastern Conference had four teams in the top 10 and five of the top 12. Alabama and Georgia are the SEC's only two in the top 10 this week.

The Atlantic Coast Conference's first absence from the top 20 in 10 years lasted only a week thanks to Wake Forest moving up to No. 19.

SEC -- 7 (Nos. 1, 2, 13, 16, 17, 18, 20).

Big Ten -- 5 (Nos. 3, 4, 7, 9, 11).

ACC -- 2 (Nos. 19, 23).

Big 12 -- 3 (Nos. 6, 12, 21).

Pac-12 -- 2 (Nos. 8, 22).

American -- 2 (Nos. 5, 24).

Sun Belt -- 1 (No. 15).

Mountain West -- 1 (No. 25).

Independents -- 2 (Nos. 10, 14).

RANKED vs. RANKED

No. 4 Penn State at No. 3 Iowa. This isn't the same Nittany Lions team that lost by 20 points to Iowa last year.

No. 6 Oklahoma vs. No. 21 Texas. Red River Rivalry will be hard-pressed to duplicate last year's four-overtime thriller won by the Sooners.

No. 13 Arkansas at No. 17 Mississippi. These are a couple of teams looking for a re-set after lopsided losses to the nation's best two.

No. 2 Georgia at No. 18 Auburn. Bulldogs have won 12 of 15 in the series.