Amid the excitement of two conferences returning to play, Week 8 brought a critical result in the Big 12 and a massive upset to begin the Big Ten season.

Oklahoma State knocked off Iowa State and trimmed the group of Big 12 unbeatens to two. Later in the afternoon, Indiana celebrated a walk-off two-point conversion to stun Penn State and snap a 42-game losing streak against Top 10 teams.

North Carolina and Michigan also earned victories over ranked teams, but Virginia Tech fell to unranked Wake Forest. Those results headlined the changes in B/R's Top 25.

Our five-man panel of experts—David Kenyon, Adam Kramer, Kerry Miller, Joel Reuter and Brad Shepard—each submitted a Top 25 ballot for Week 7. A first-place vote is worth 25 points, a second-place vote is worth 24 points, etc.

B/R Week 8 Top 25

1. Clemson (Last Week: 1)
2. Alabama (2)
3. Ohio State (3)
4. Notre Dame (5)
5. Georgia (4)
6. Oklahoma State (T-7)
7. Cincinnati (T-12)
T-8. Michigan (17)
T-8. Wisconsin (T-12)
T-10. Oregon (T-7)
T-10. Texas A&M (9)
12. Miami (10)
13. BYU (11)
14. Florida (14)
15. North Carolina (15)
16. Indiana (NR)
17. Coastal Carolina (21)
18. Marshall (23)
19. Kansas State (NR)
20. USC (25)
21. Liberty (NR)
22. Penn State (6)
23. Arkansas (24)
24. SMU (16)
25. Army (NR)

Others receiving votes: Memphis, Boise State, Northwestern, Rutgers

Who's Hot: Big 12 Front-Runners

Since both Oklahoma and Texas already have two conference losses, the Big 12 is officially someone else's to lose. Right now, someone else is either Oklahoma State or Kansas State.

Oklahoma State grabbed the biggest win of the weekend, toppling Iowa State 24-21 in a battle of unbeaten Big 12 teams. Sophomore quarterback Spencer Sanders made his return from a leg injury and accounted for 306 total yards in the victory.

Additionally, the Cowboys limited Brock Purdy to a meager 4.8 yards per pass. Iowa State still rushed for 227 yards, but a one-dimensional offense kept the Cyclones in check.

Oklahoma State—which improved to 4-0 overall and rose to No. 6 in the B/R Top 25—is slated to host Texas next weekend.

Six weeks ago, Kansas State lost to Arkansas State. At that moment, it seemed the Wildcats wouldn't be anything close to a contender in the Big 12. Yet after demolishing rival Kansas 55-14 in Week 8, they've now earned four straight conference wins.

Saturday, they found the end zone in all three phases. Justin Gardner had a pick-six, Phillip Brooks returned two punts for touchdowns, and the offense scored four times. K-State is now 4-1, ranked 19th by B/R and readying for a trip to West Virginia.

But we're peeking ahead.

On the first weekend of November, Kansas State hosts Oklahoma State. The winner will officially be the Big 12 front-runner.

Who's Not: Minnesota's New-Look Defense

Before the 2020 NFL draft, the last time Minnesota had four defensive players selected was 1969. Between that quartet—which included star safety Antoine Winfield Jr.—moving on and four other key seniors departing, the Gophers had to rebuild the defensive side of the ball this season.

The first look, well, it wasn't awesome.

Michigan cruised to a 49-24 victory behind quarterback Joe Milton, who completed 15 of 22 passes for 225 yards and a touchdown in his first career start. He added 52 yards and a score on the ground, which is where the Wolverines controlled the game.

Hassan Haskins picked up 82 yards and two touchdowns on six carries, while Zach Charbonnet rushed for 70 yards and a score on four attempts. Blake Corum chipped in 21 yards, and Chris Evans provided 19 yards and a touchdown on five carries each.

Minnesota forced only seven third-down situations, and Michigan converted four of them. In total, the Gophers surrendered 478 yards—more than they allowed in 12 of 13 games last season.

Although the Gophers can still chase down Wisconsin in the Big Ten West race, they're no longer in B/R's Top 25.

Fun Fact: Mertz, Fields Both Finish 20-of-21

Being a quarterback is incredibly hard, yet Wisconsin's Graham Mertz and Ohio State's Justin Fields made it look easy.

Mertz—in his first career start—completed his first 17 passes and helped Wisconsin rout Illinois 45-7. The redshirt freshman ended 20-of-21 for 248 yards and five touchdowns. As if that's not impressive enough, the only incompletion was a drop.

Despite his lack of experience, Mertz looked comfortable all game.

"It's good to see that he's got that confidence," tight end Jake Ferguson said, per Josh Schafer of 247Sports. "And like I said, man, he's smooth for sure."

Fields matched Mertz's completion rate, guiding Ohio State to a 52-17 triumph over Nebraska. Fields passed for 276 yards and two scores, adding 54 yards and a touchdown on the ground.

The competition will be tougher soon—especially for Ohio State, which travels to Penn State next weekend—but Mertz and Fields offered clear reminders of why Wisconsin and Ohio State are favored to reach the Big Ten Championship Game.

What to Watch For: Showdown at Penn State

Penn State is looking for redemption.

In last season's matchup with Ohio State, the Nittany Lions had a chance to move a win away from securing a place in the Big Ten title game. But it was a forgettable day for quarterback Sean Clifford.

All five of Penn State's first-half possessions ended with a punt. Then, on the opening drive of the third quarter, he exited with an apparent leg injury. Clifford mustered only 71 yards on 17 pass attempts, leaving the game with the Nittany Lions trailing 21-0. Ohio State ended up winning 28-17 and clinched the division.

And the 2020 campaign didn't start as Clifford hoped, either.

Penn State lost to Indiana 36-35 in overtime on an incredible and controversial two-point conversion. Though the Nittany Lions still have championship dreams, those suddenly hinge on upsetting Ohio State. Penn State cannot afford a second loss.

The Buckeyes, however, would love to eliminate their rival.

Expected to finish no worse than 7-1, Ohio State could take a commanding two-game edge on Penn State with a tiebreaker. Michigan and Indiana—and, hey Rutgers is 1-0!—would become the primary challengers for the Buckeyes in the Big Ten East.

Kickoff is slated for 7:30 p.m. ET on ABC next Saturday.