IOWA CITY, Iowa (AP) — On the surface, it appears as though No. 22 Iowa's resurgence has been fueled by the so-called "New Kirk Ferentz."

In reality, the Hawkeyes are better because their defense is better — and knocking opponents around has been the foundation of every good team coached by Ferentz.

Iowa (5-0, 1-0 Big Ten) surged back into the Top 25 for the first time in five years this week following one of the best defensive performances in Ferentz's 17-year run in Iowa City.

The Hawkeyes forced four turnovers and held then-No. 19 Wisconsin out of the end zone in a 10-6 win in Madison, cementing Iowa's status as a legitimate contender in the Big Ten West.

Iowa, ranked 15th nationally with just 15.4 points allowed per game, will look for its sixth straight win Saturday when it hosts border rival Illinois (4-1, 1-0).

"The credit goes to our players. These guys are working their tails off right now, and they're all contributing in their way. And when you get that going, you have a chance," Ferentz said.

Ferentz's new, more forward-thinking approach — which has included much more aggressive approaches to recruiting and game-planning — has energized the program.

The one thing that hasn't changed is a commitment to hard-nosed defense.

The Hawkeyes weren't playing that way a year ago.

Despite the presence of a pair of future NFL players on its line in Carl Davis and Louis Trinca-Pasat, Iowa was wildly inconsistent a year ago. Its defense bottomed out at the end of the year, allowing 82 points in losses to Nebraska and Tennessee.

Iowa's biggest issue was on the perimeter. Opponents ran wild on the Hawkeyes outside, and their inexperienced linebackers seemed powerless to stop them.

But the line has more than made up for the losses of Davis and Trinca-Pasat, and linebackers Ben Neimann, Josey Jewell and Cole Fisher have made remarkable strides this season.

Iowa is the only team in the nation that hasn't given up a rushing touchdown, and its 2.6 yards per carry allowed is 10th.

Wisconsin was threatening to break that streak in the fourth quarter last week, but end Nate Meier helped force a fumble near the goal line that preserved the win.

"He's playing his best football, and again, for us to have a good football team, our seniors need to be humming, and he's doing that," Ferentz said.

The Hawkeyes also have witnessed solid play out of their secondary.

Junior Desmond King has blossomed into one of the country's best cornerbacks and an early favorite for Big Ten Defensive Player of the Year honors.

He shared the league's player of the week honor Monday after recording nine tackles, two pass break-ups and two interceptions in the win over the Badgers.

King, who has also been a standout in the return game, is tied for the national lead with five interceptions — despite opponents avoiding a throw his way as much as possible.

"It's our third Big Ten recognition for a player this season," Ferentz said. "If you look at it, it's an offensive player, defensive player and a special teams player, and really that's kind of how we're winning right now. We're playing good team football."

Iowa might need its defense to carry it again this weekend, since injuries to top wide receiver Tevaun Smith (knee sprain) and left tackle Boone Myers (shoulder stinger) will likely keep them out against the Illini.

The Hawkeyes don't seem to mind using that as a winning formula.

After all, it's been one Ferentz has leaned on for years.

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