Big Ten power rankings: Week 8

There's a new No. 1 after Ohio State's stumble in Madison, and the ripple effects are being felt throughout the power rankings. The league title race is totally wide open and things are getting very interesting heading toward the home stretch.

Let's take a look.

1. Michigan State (7-0, 3-0 Big Ten): Only one unbeaten team remains in the Big Ten, and it's the surging Spartans. Michigan State came out flat on offense but poised on defense against Illinois and surged in the second half. Mark Dantonio's team continues to make fewer mistakes than its opponents and continues to execute in all three phases. The next challenge is winning games outside the state for the first time this season. Michigan State hits the road the next two weeks.

2. Wisconsin (6-1, 2-1): Bret Bielema's big-game blues are over and Wisconsin has put itself back in the Big Ten title picture after an impressive performance against Ohio State. Wisconsin got back to winning the Wisconsin way, a good sign heading into a game against a mirror-image opponent -- Iowa. Bielema got over the hump against an elite team at home. The next step: Can he lead the Badgers to a signature road win?

3. Iowa (5-1, 2-0): The Hawkeyes handled their business in Ann Arbor despite allowing more than 500 yards of offense to the Wolverines. They capitalized on Michigan's mistakes and showcased a balanced and dynamic offense with quarterback Ricky Stanzi and running back Adam Robinson. The Hawkeyes now return home for the first of three showcase games at Kinnick Stadium as Wisconsin visits.

4. Ohio State (6-1, 2-1): It's odd to see the Buckeyes drop down this far, but they looked overmatched for most of Saturday night's game at Camp Randall Stadium. The only thing more surprising than Ohio State's continued breakdowns on special teams is the way the defensive line got steamrolled by Wisconsin's big and talented offensive front. Ohio State can still help shape the league title race, but it has no margin for error.

5. Purdue (4-2, 2-0): Surprise, surprise. Few would have envisioned a 2-0 start to league play several weeks ago, but Purdue continues to make strides on both sides of the ball. Freshman quarterback Rob Henry delivered another impressive performance against Minnesota and got help from running back Dan Dierking. Purdue could get a rude awakening this week at Ohio State, but life is good right now.

6. Illinois (3-3, 1-2): The final score looked ugly, but Illinois continued to show progress on the defensive side, shutting down a very potent Michigan State rushing attack. Quarterback Nathan Scheelhaase still looks like a freshman at times, and his miscues certainly cost Illinois in the second half. But this is a much improved team that can do some damage during a favorable second-half schedule.

7. Northwestern (5-1, 1-1): The bye week came at a good time for Northwestern, which needs to figure out how to stop beating itself before taking aim at unbeaten Michigan State. The Wildcats typically pull off one significant upset per year, but they'll need to be much more polished and avoid penalties and turnovers when the Spartans visit Ryan Field.

8. Michigan (5-2, 1-2): Rich Rodriguez's offense clearly isn't the problem. Even after starting quarterback Denard Robinson hurt his shoulder Saturday, the Wolverines continued to move the ball against a very good Iowa defense with Tate Forcier at the helm. But a great offense combined with weak defense and woeful special teams simply isn't a formula for success in the Big Ten. Michigan has to spend the bye week finding some way to improve its D and its kicking game before a trip to Happy Valley.

9. Indiana (4-2, 0-2): Bill Lynch's crew made it through the nonconference slate at 4-0, but not without a scare on Saturday from Arkansas State. Like Michigan, Indiana has no trouble piling up yards and points on offense. But can the Hoosiers expect to win in the Big Ten if their defense doesn't significantly improve? It's one thing to let Denard Robinson go crazy, but Arkansas State's Ryan Aplin had a huge performance against IU. I still think Indiana makes a bowl this year, but the defense has to make strides soon.

10: Penn State (3-3, 0-2): The Nittany Lions really needed a week to regroup after an ugly home loss to Illinois and the finger-pointing that ensued after the game. Key injuries throughout the defense really put the spotlight on the offense to get things together. It's time for Evan Royster to look like an All-Big Ten running back again, and Penn State has to start getting creative to put up points because the defense likely will have some ups and downs the rest of the way.

11. Minnesota (1-6, 0-3): The tough times continue in the Twin Cities, as six straight losses have brought the end for fourth-year coach Tim Brewster. Minnesota needs to win out just to get bowl eligible, and with Ohio State, Iowa and Michigan State still on the schedule, it's hard to imagine. The Gophers don't quit in games, but they still make far too many mistakes to win them.