Big Ten power rankings: Week 8

Posted by ESPN.com's Adam Rittenberg

There's a new top dog in the Big Ten, and the rankings have a different look as the home stretch beckons. Iowa and Michigan State make the biggest moves this week, and the league's two hottest teams meet Saturday night at Spartan Stadium.

1. Iowa (7-0, 3-0) -- The Hawkeyes are for real, and they established themselves as the team to beat in this league with another come-from-behind win at Wisconsin. It's looking more and more like a special season for the black and gold, and if quarterback Ricky Stanzi builds on his steadiest performance of the season, Iowa will continue to win games. Nothing intimidates these Hawkeyes, and they seem to thrive on adversity.

2. Penn State (6-1, 2-1) -- Tom Bradley's defense is one of the best in the country, and when linebacker Sean Lee gets fully healthy, look out. We still haven't gotten a great read on Penn State since the Iowa loss, but to the Lions' credit, they've taken care of business against inferior competition. Things get a lot tougher this week at Michigan, where Penn State always struggles.

3. Ohio State (5-2, 2-1) -- The Buckeyes' season-long problems on offense finally caught up with them in a mistake-ridden loss to Purdue. Ohio State now must win out to have any chance of winning or sharing its fifth consecutive Big Ten championship. The defense is good enough to win a BCS bowl, but quarterback Terrelle Pryor and the offense really need to pick things up immediately.

4. Michigan State (4-3, 3-1) -- After a slow start, the Spartans have turned the corner on defense and survived some injuries on offense to win three straight league games. If they can upset Iowa on Saturday night, they're certainly in the picture for the league title, which looked like a long shot three weeks ago. Mark Dantonio's squad gets rewarded in this week's rankings.

5. Wisconsin (5-2, 2-2) -- The Badgers drop one spot after their second straight loss to a ranked opponent. Even in defeat, Wisconsin has shown some bright spots, especially on an aggressive defense led by end O'Brien Schofield. But quarterback Scott Tolzien has struggled after a hot start to the season.

6. Michigan (5-2, 1-2) -- Despite a record-setting offensive performance against Delaware State, Michigan remains in the No. 6 hole. The Wolverines can make a serious move this week by knocking off Penn State in Ann Arbor. The playmakers are there on offense, but Michigan must show progress on defense in the second half of the season after enduring too many breakdowns.

7. Minnesota (4-3, 2-2) -- Inconsistency on offense has plagued the Gophers throughout the season, and it's clear players are still adjusting to the pro-style system. The defense is clearly better, especially at the linebacker position, but Minnesota needs improved play from quarterback Adam Weber and some more playmakers to emerge.

8. Northwestern (4-3, 1-2) -- This just doesn't seem like Northwestern's year, as injuries have ravaged the defense and the offense is clearly missing the playmakers who graduated. The Wildcats' offense piles up yards but lacks the big-play ability to get to the end zone. If Northwestern wants to reach back-to-back bowls, it must beat Indiana on Saturday.

T-9 Purdue (2-5, 1-3) -- The Big Ten's hard-luck team finally got rewarded with a huge victory against Ohio State. Purdue's big-game blues are over after 19 consecutive losses to ranked opponents. Danny Hope tells me the momentum has been building for several weeks, and the Boilers could be very dangerous down the stretch.

T-9 Indiana (4-3, 1-2) -- Ben Chappell and the Hoosiers bounced back nicely from a horrendous performance at Virginia and took care of business against Illinois. Chappell set career highs in both passing yards (333) and passing touchdowns (3) as Indiana restored its bowl hopes heading into a big game at Northwestern.

11. Illinois (1-5, 0-4) -- The Illini remain in the final spot, but there's even more distance between them and the rest of the league. Illinois is once again the Big Ten's biggest disappointment, and the frustration has reached new heights for embattled head coach Ron Zook and his players. A loss this week against Purdue could be the breaking point for this team.