Ohio State hasn't been dominant or error-free the past two weeks, but the Buckeyes keep finding ways to win. Urban Meyer remains unbeaten in Columbus after an extremely hard-fought game at Northwestern, as Ohio State had to rally from halftime and fourth-quarter deficits.

Knock the Buckeyes if you'd like, but they've won 18 consecutive games, the longest streak in the nation.

It could turn out that the Buckeyes' past two opponents, Wisconsin and Northwestern, both could make cases for being the league's No. 2 squad. We've been more impressed with the one-loss Wildcats than undefeated Michigan, which gets its own shot at Ohio State on Nov. 30 at the Big House. Not much separates Northwestern, Michigan and Wisconsin right now.

Michigan State and Indiana make positive moves in the rankings, while Iowa, Penn State and Minnesota fall.

Let's take one final look at the Week 5 Power Rankings.

Here's this week's rundown ...

1. Ohio State (6-0, 2-0 Big Ten; last week: 1): For a while it looked like Ohio State's run of perfection would come to an end Saturday night. Quarterback Braxton Miller looked rattled, and Northwestern moved the ball well against the Buckeyes' defense. But Ohio State regrouped midway through the third quarter and made enough plays on both sides of the ball to survive another tough test. Meyer stuck with Miller after considering Kenny Guiton, running back Carlos Hyde had a big night and the young Buckeyes defense stopped the run when it needed to in the fourth quarter.

2. Northwestern (4-1, 0-1; last week: 2): The talent differential that plagued Northwestern for years isn't there as much anymore, as the Wildcats can keep pace with any team in the league. The problem: They still struggle to finish big games. They might have been a yard away from upsetting Ohio State but couldn't convert a fourth-and-1 in plus territory. The inability to finish drives cost Pat Fitzgerald's crew, which held Ohio State's offense out of the end zone for nearly three quarters. Venric Mark provided a big boost in his return from injury.

3. Michigan (5-0, 1-0; last week: 4): Michigan needed a clean game and got one against Minnesota, as the Wolverines had zero turnovers in a 42-13 victory. Quarterback Devin Gardner was efficient in the pocket, and tight end Devin Funchess had career highs in both catches (seven) and receiving yards (151). Michigan's defense settled down nicely after allowing an early touchdown, as Minnesota couldn't get the explosion plays it needed to hang around. The Wolverines head back on the road this week in Happy Valley.

4. Wisconsin (3-2, 1-1; last week: 3): The Badgers had an extra week to think about their missed opportunities at Ohio State before resuming play with another big game against Northwestern. Standout running back Melvin Gordon is expected back from a knee injury, and the off week came at a good time to boost the team's overall health. Wisconsin's defense had some struggles against Ohio State's spread offense and faces another spread team this week in Northwestern.

5. Nebraska (4-1, 1-0; last week: 5): Although the Huskers didn't move up in the rankings, we feel better about their ability to rise up after seeing their defense step up against a big-play Illinois offense. Young defenders like Jared Afalava, Michael Rose and Randy Gregory performed well, and veteran nickelback Ciante Evans had two tackles for loss and a forced fumble. Nebraska's biggest issue might be at quarterback, as freshman Tommy Armstrong Jr. delivered in place of the hobbled Taylor Martinez. Armstrong received plenty of help from running back Ameer Abdullah (225 rush yards, 2 TDs).

6. Michigan State (4-1, 1-0; last week: 7): We knew the Spartans had a defense, which showed up big in the second half at Iowa, especially against the run. The big news is the Spartans also have a quarterback in Connor Cook, who passed for 277 yards and two touchdowns, finding both Macgarrett Kings Jr. and Bennie Fowler for big plays. Cook was visibly upset at Notre Dame, questioning the coaches' faith in him after being pulled on the final drive. He restored that faith Saturday and put Michigan State in position to challenge for a division title.

7. Iowa (4-2, 1-1; last week: 6): Mark Weisman and the power run game had been Iowa's identity through the first five weeks. But Michigan State stopped Weisman (seven carries, 9 yards) and completely shut down Iowa's offense in the second half. The Hawkeyes once again fell victim to a special-teams fake and couldn't stop big pass plays from Michigan State. Several injuries mounted up for Iowa, and while most don't appear to be serious, the open week comes at a good time before a trip to Ohio State.

8. Indiana (3-2, 1-0; last week: 11): The off week clearly paid off for Kevin Wilson's crew, which breathed life back into its bowl hopes with an excellent performance against Penn State. Quarterback Nate Sudfeld (321 pass yards, 2 TDs) bounced back nicely from his struggles against Missouri, wide receiver Cody Latimer (nine catches, 140 yards, fumble recovery) had a huge day and the defense contained Penn State's run game. Indiana's offense faces a much bigger test this week at Michigan State, but the Hoosiers head to East Lansing with some confidence.

9. Penn State (3-2, 0-1, last week: 8): Bill O'Brien's team has some serious problems after falling to Indiana for the first time in team history. The defense didn't show up against a spread offense for the second time in three games, and Indiana completely dominated the fourth quarter. Penn State has something special with Christian Hackenberg and wide receiver Allen Robinson, but the defense clearly has taken a step back. Things only get tougher with Michigan and Ohio State up next.

10. Illinois (3-2, 0-1; last week: 9): There's no doubt Illinois has improved this season, but by how much? The Illini never mounted a serious challenge against Nebraska, even though the Huskers played without Martinez, as Tim Beckman's crew fell behind 30-5 early in the third quarter. Illinois quarterback Nathan Scheelhaase has gone from great (Cincinnati) to shaky (Washington) to great (Miami University) to shaky (Nebraska). But the bigger issue is a defense that surrendered 335 rush yards to the Huskers. Illinois is off this week before a critical home stretch against Wisconsin and Michigan State.

11. Minnesota (4-2, 0-2; last week: 10): It has been a rough few weeks both on and off the field for the Gophers, who dropped their second straight game and played without head coach Jerry Kill, who remained in Minneapolis after suffering another seizure Saturday morning. Minnesota enters an off week, which will put more attention on Kill and his health. The Gophers once again lack enough explosiveness on offense to do much damage against Big Ten defenses. Minnesota resumes play Oct. 19 at Northwestern.

12. Purdue (1-4, 0-1; last week: 12): The open week gave Darrell Hazell's crew a chance to regroup. Unfortunately, an off-field issue surfaced involving wide receiver B.J. Knauf, who has been suspended for the next two games. It will be interesting to see how freshman quarterback Danny Etling performs after some time to practice as the starter. Purdue's struggling defense will be tested again as the high-powered Nebraska Cornhuskers visit Ross-Ade Stadium.