The September slate will come to a close on Saturday in a big way with key conference and top 25 matchups throughout the country. The early window features five games involving ranked teams, two top 25 matchups in the afternoon and a massive Big Ten showdown will take you into the night in Lincoln.

How should you navigate the day? Here's a viewer's guide for your college football Saturday. 

All times Eastern; games played Saturday unless otherwise noted.

The biggest games

No. 18 Virginia at No. 10 Notre Dame, NBC, stream on FuboTV (Try for free) 3:30 p.m.: The Fighting Irish hope to rebound from last Saturday's emotional loss to Georgia against a Cavaliers team that didn't exactly look sharp last weekend in a win over Old Dominion. Keep an eye on how Virginia's stout rush defense gets after a Notre Dame rushing attack that has been less than stellar.

No. 21 USC at No. 17 Washington, Fox, stream on FuboTV (Try for free) 3:30 p.m.: The revolving door of quarterbacks hasn't stopped the Trojans from making the top 25. Matt Fink has gone from third-string to starter after JT Daniels suffered a season-ending knee injury in Week 1 and Kedon Slovis got knocked out of last week's win over Utah. He might have to go score-for-score in a shootout against the Huskies. Quarterback Jacob Eason can sling it and has a great set of receivers.

No. 5 Ohio State at Nebraska, ABC, 7:30 p.m.: The biggest game of Scott Frost's two-year tenure with the Cornhuskers will take place Saturday night, and it'll be against an Ohio State team that not only has a star at quarterback in Justin Fields, but has fixed its biggest problem from last year -- the defense. Will the Nebraska fans rattle the Buckeyes? We'll see. This is the biggest road game of Fields' career.

Ole Miss at No. 2 Alabama, CBS, 3:30 p.m.: Coach Nick Saban and the Crimson Tide will take the big stage on the SEC on CBS for the second time this season, and will do so against the Rebels, who were the last team to topple the Tide inside Bryant-Denny Stadium. Keep an eye on how quarterback Tua Tagovailoa and his talented receivers attack one of the worst pass defenses in the country.

Other big games

No. 1 Clemson at North Carolina, ABC, 3:30 p.m.: The shine of this one got worn off a bit after the Tar Heels fell to Appalachian State last weekend, but there's still plenty to keep an eye on with the Tigers rolling into town. We are all stunned that quarterback Trevor Lawrence has tossed five interceptions, and he'll have to cut back on those if they plan on repeating as national champs.

Texas Tech at No. 6 Oklahoma, Fox, stream on FuboTV (Try for free) noon: The Sooners return after a week off, and will get the first chance of the day to make an impression. Quarterback Jalen Hurts leads the nation in passing efficiency (250.20), and has emerged as one of the top contenders for the Heisman Trophy. Quietly, Texas Tech boasts the second-best pass defense in the Big 12 (133.7 YPG). This one should be fun. 

Northwestern at No. 8 Wisconsin, ABC, noon: Running back Jonathan Taylor and the rest of the Badgers made a big statement in the 35-14 win over Michigan next week, and the Northwestern passing attack has been nothing short of dreadful this season (one touchdown, six interceptions). Let's see if the Badgers take care of a lesser opponent like championship teams do.

Washington State at No. 19 Utah, FS1, stream on FuboTV (Try for free) 10 p.m.: The Cougars just wasted a nine-touchdown performance from quarterback Anthony Gordon, and the Utes just dropped a big Pac-12 South showdown against USC. Pac-12 After Dark will be big for both teams this weekend. Stay up late, put some coffee on and let's get weird.

No. 24 Kansas State at Oklahoma State, ESPN+, 7 p.m.: The Wildcats sit at 3-0 and now have to go to Stillwater to face off against a mad Cowboys squad that dropped a wild one at Texas last week. Consider this a show-me game for which team will be a threat once the leaves change color.

Keep an eye on...