The top half of the Power Rankings remains virtually unchanged, as Big Ten kingpin Ohio State rallied to beat Iowa, Wisconsin stomped Illinois, and the Michigan schools held serve in vastly different ways (all defense for Michigan State, all offense for Michigan).

The changes come in the league's second tier, as Northwestern continues its shocking tumble after a home loss to Minnesota, which moves up three spots. Iowa actually moves up despite a loss, as we liked the Hawkeyes' game plan and execution against Ohio State. Indiana also holds steady after nearly winning a shootout at the Big House.

Let's take one final look at the Week 7 rankings.

Now for the fresh rundown ...

1. Ohio State (7-0, 3-0 Big Ten; last week: 1): Another test passed for Ohio State, which overcame a plucky Iowa team with a stellar second half behind quarterback Braxton Miller (222 pass yards, 2 TDs, 102 rush yards) and running back Carlos Hyde (149 rush yards, 2 TDs). The Buckeyes also survived the ejection of star cornerback Bradley Roby in the first quarter and limited Iowa's offense to one big play in the second half. The defense once again will be challenged this week as Christian Hackenberg, Allen Robinson and Penn State visit Columbus.

2. Wisconsin (5-2, 3-1; last week: 2): Ohio State retains its spot atop the rankings with a perfect record, but Wisconsin has looked like the Big Ten's most dominant team of late. After crushing Northwestern at Camp Randall Stadium, the Badgers went on the road and steamrolled Illinois, as running backs Melvin Gordon (142 rush yards, 3 TDs) and James White (98 rush yards, 2 TDs, 29 receiving yards, 1 TD) did their thing and Joel Stave had an extremely efficient performance (16 of 21 passing, 189 yards, 2 TDs). The second open week comes at a good time as linebacker Chris Borland must get healthy for the stretch run, which features some tricky games.

3. Nebraska (5-1, 2-0; last week: 3): The Huskers might be the Legends Division favorite at this point, as they get Michigan State at home. Quarterback Taylor Martinez should make his return from turf toe this week against Minnesota as Nebraska tries to keep building momentum before the season's defining month. Martinez needs some work before the schedule gets tougher, and the Huskers' offensive line plays its first game without standout guard Spencer Long.

4. Michigan State (6-1, 3-0; last week: 4): A shutout of Purdue wasn't surprising. Neither was another defensive touchdown, Michigan State's fifth of the season, courtesy of linebacker Denicos Allen. But Michigan State's offense took a step backward, as the line struggled to control Purdue's defensive front and Connor Cook completed only 13 passes for 107 yards. The Spartans will need to be sharper this week against Illinois and particularly when the schedule gets tougher in November.

5. Michigan (6-1, 2-1; last week: 5): We think Jeremy Gallon just caught another long pass. Gallon set a Big Ten single-game record with 369 receiving yards (second most in FBS history), while quarterback Devin Gardner set team records for pass yards (503) and total yards (584) and accounted for five total touchdowns. Running back Fitzgerald Toussaint added 151 yards and four touchdowns. Michigan needed all the offense to win a shootout with Indiana at the Big House. As for the defense? A problem for another day. Michigan has two weeks to prepare for its Nov. 2 showdown at Michigan State.

6. Penn State (4-2, 1-1; last week: 7): The off week came at a good time for Penn State after a physically and emotionally draining four-overtime win against Michigan. The Lions had more diversity in their passing game against the Wolverines and will need the same -- as well as strong run production -- to keep pace with Ohio State on Saturday in Columbus. Penn State has won two of its past three games at Ohio Stadium and could play spoiler down the stretch in Leaders Division play.

7. Iowa (4-3, 1-2; last week: 8): Credit Iowa for an excellent game plan coming off the open week. The Hawkeyes racked up 17 first-half points against Ohio State and controlled the line of scrimmage on both sides of the ball. Ultimately, better talent won out as Iowa couldn't keep pace with Miller, Hyde and the Buckeyes, but the Hawkeyes certainly could make some noise down the stretch in the wide-open Legends Division. Sophomore tight end Jake Duzey (6 receptions, 138 yards, 1 TD) gives Jake Rudock another weapon in the passing game. Iowa returns home this week to face sputtering Northwestern.

8. Minnesota (5-2, 1-2; last week: 11): The bye week clearly paid off for Minnesota, and so did a halftime pep talk from coach Jerry Kill, who made his presence felt at Ryan Field without being on the sideline. Minnesota dominated the line of scrimmage, as defensive tackle Ra'Shede Hageman, running back David Cobb and quarterback Philip Nelson, who relieved Mitch Leidner, stepped up in the final three quarters. The Gophers took advantage of a short-handed Northwestern team and overcame several bad calls to record a big road win. Up next: Nebraska at home.

9. Indiana (3-4, 1-2; last week: 9): The Hoosiers are high on entertainment value, boasting the Big Ten's best quick-strike offense and quite possibly the league's best group of wide receivers. But all those highlights and points still aren't translating to enough wins. It's the same movie with IU, with an A-plus offense and a D-minus defense, which surrendered an unacceptable 63 points and 751 yards to Michigan on Saturday. Tre Roberson was brilliant at Michigan and seemed to pass by Nate Sudfeld in the quarterback pecking order. But the defense remains the team's top priority entering the open week.

10. Northwestern (4-3, 0-3; last week: 6): The free-fall continues for a Wildcats team that was No. 2 in the power rankings just two weeks ago. Remember when Northwestern held a fourth-quarter lead against Ohio State? Key injuries certainly have played a role in Northwestern's downfall, but quarterback Trevor Siemian seems to be regressing and so is the offensive line. A bowl game suddenly is no guarantee for the Wildcats, who need to get Kain Colter and Venric Mark healthy and refocus for the stretch run. They visit Iowa this week.

11. Illinois (3-3, 0-2; last week: 10): The Illini needed a fast start coming off the open week against Wisconsin but stumbled out of the gate, falling behind 21-0 on their home field before course-correcting in the second quarter. Quarterback play wasn't the issue, as Nathan Scheelhaase and Reilly O'Toole combined to complete 25 of 32 passes for 318 yards, but two fumbles led to Wisconsin touchdowns and Illinois' defense couldn't slow down the Badgers. The Illini need at least one upset down the stretch to have a chance to reach six wins and a bowl.

12. Purdue (1-6, 0-3; last week: 12): Darrell Hazell's squad can build on Saturday's road performance against Michigan State, especially a Boilers defense that allowed just one score and repeatedly penetrated the backfield. The offense had several chances but couldn't finish drives in Spartans territory. Purdue needs to clean up its pass protection after allowing five sacks, but if Bruce Gaston Jr. and the defensive front continues to step up, a win could be coming down the stretch. The Boilers have a week off before hosting Ohio State.