Big Ten power rankings: Week 9

Posted by ESPN.com's Adam Rittenberg

There’s clear separation at the top after Saturday’s games. Wisconsin and Michigan State are solid in the four and five spots. After that, it gets pretty messy until the bottom, as evidenced by a three-way tie at No. 7.

1. Iowa (8-0, 4-0): Kirk Ferentz would love a 20-point win right about now, but he’ll certainly take what he’s getting from his incredibly resilient team. It looked like Michigan State’s hook-and-lateral play would end Iowa’s perfect season, but junior quarterback Ricky Stanzi responded with a 70-yard drive, capped by a scoring pass to Marvin McNutt with no time left on the clock. What magic does Iowa have in store down the stretch as it chases perfection?

2. Penn State (7-1, 3-1): The Lions are a very dangerous team right now, and they gained a huge confidence boost by winning at Michigan Stadium for the first time since 1996. Senior quarterback Daryll Clark has been masterful since the Iowa loss, and weapons are emerging around him in Graham Zug, Andrew Quarless and others. A win this week against Northwestern sets up a huge game against Ohio State on Nov. 7.

3. Ohio State (6-2, 4-1): There was plenty of angst at halftime Saturday against Minnesota, but Terrelle Pryor and the Buckeyes totally dominated the final 30 minutes. Pryor turned in arguably his best half of the season, and wide receiver DeVier Posey is looking more and more like a star. Thaddeus Gibson (three sacks) led another ferocious defensive effort. Ohio State must continue to build confidence on offense this week before heading to Happy Valley.

4. Wisconsin (5-2, 2-2): The Badgers were idle on Saturday but move up a spot in the rankings. After back-to-back losses before the bye, Bret Bielema’s crew needs to get back on track at home against surging Purdue. Quarterback Scott Tolzien has thrown five interceptions and no touchdowns in his last two games and must be careful against a Boilers defense that has started to force turnovers.

5. Michigan State (4-4, 3-2): One play can make a huge difference in a season, and Michigan State once again found itself on the wrong end Saturday night. The Spartans defense was suffocating until the final 1:37 and left the inside route open for McNutt on the game’s decisive play. I still think this program will do big things in the future, but losses like Saturday’s reinforce that Michigan State hasn’t arrived.

6. Minnesota (4-4, 2-3): It’s very hard to know where to slot the Golden Gophers at this point. They’ve made some strides on defense this year but remain mistake-prone and offensively challenged. Life without wide receiver Eric Decker (ankle) could be downright miserable if Minnesota doesn’t shake things up on offense. It might be time for MarQueis Gray at quarterback. Minnesota needs to get things turned around at home, where it plays its next three games.

T-7 Northwestern (5-3, 2-2): If every game started with Northwestern down 18 to 25 points, the Wildcats might be undefeated right now. Throughout the season they’ve played their best in seemingly desperate situations. This team clearly has a lot of flaws, but heart isn’t one of them. A banged-up defense has made strides since the Minnesota loss on Sept. 26, and if a running game emerges, Northwestern could win a few more games.

T-7 Michigan (5-3, 1-3): The Penn State game confirmed Michigan isn’t ready for prime time yet, as the Wolverines looked sloppy on both sides of the ball. Youth and depth were Rich Rodriguez’s big concerns entering the year, and both factors are hurting the team right now. Rodriguez needs to get quarterbacks Tate Forcier and Denard Robinson back on track. Perhaps more importantly, the defense needs to avoid major breakdowns.

T-7 Purdue (3-5, 2-2): Call them the Boiler Spoilers from here on out, as Purdue tries to take down higher-rated teams in the next three weeks. Purdue followed up its upset win against Ohio State with its cleanest performance of the season, a turnover-free win against Illinois. If the run game of Ralph Bolden and Jaycen Taylor can complement Joey Elliott, Purdue's offense will be dangerous, as long as it limits turnovers. The defense seems to be getting better each week.

10. Indiana (4-4, 1-3): The Hoosiers' resolve will be tested after blowing a 28-3 lead against Northwestern. Head coach Bill Lynch made several questionable decisions down the stretch, and Indiana's offense couldn't convert three second-half interceptions into any points. Indiana will need to pull off an upset against Iowa, Wisconsin or Penn State to have any chance at a bowl.

11. Illinois (1-6, 0-5): Ron Zook is coming back for another season, but this one continues to slip down the drain. Illinois shuffled quarterbacks in its loss to Purdue, struggled to stop the run and dropped its sixth game by double digits. Zook keeps trying new things to spark his team, but nothing has worked this season.