Kirk Ferentz can still recall walking into Kinnick Stadium for the 1985 matchup between No. 1 Iowa vs. No. 2 Michigan.

“The energy when you walked into the stadium that day, it’s rare,” Ferentz said. “When you get in an environment like that … there’s certain games you can feel it when you walk into the stadium, especially when the crowd gets in there.”

The Hawkeyes — with Ferentz serving as Iowa’s offensive line coach at the time — hit a game-winning field goal against the Wolverines that day to remain undefeated. Ferentz knows his team is entering another rare environment this Saturday when No. 3 Iowa (5-0) hosts No. 4 Penn State (also 5-0).

It’s almost fitting that the first top-five matchup inside Kinnick Stadium in 36 years comes against the Nittany Lions. Games in the Iowa-Penn State series always seem to be memorable — at least in the Ferentz era (since 1999).

There’s the 2002 overtime game, the 6-4 finish, Daniel Murray’s field goal, Adrian Clayborn’s blocked punt, Trace McSorley’s walk-off touchdown pass, and more.

Ferentz picked up his 100th Big Ten win as a head coach in last season’s victory over Penn State.

Iowa is 4-1 in its last five games against top-five teams at Kinnick Stadium. The lone loss in that stretch was to No. 4 Penn State in 2017. The Hawkeyes are hoping to take advantage of their moment against this season’s No. 4 Nittany Lions.

“It’s a great opportunity,” Iowa quarterback Spencer Petras said. “It’s important to not make it more than it is. It is just a football game. We’ve played five, and this is our sixth one. But it’s a big deal. It’s going to be a lot of fun. … This is why you play football, for games like this.”

Containing Clifford in the pocket, and defending his favorite target

Iowa’s defense has sent four of the five starting quarterbacks it has played this season to the bench before the end of the game.

“It’s given us a lot of confidence,” safety Kaevon Merriweather said. “I think we understand what we need to do. I think we’re an experienced group now, with a young defensive line they have a lot more experience going on game six. We understand what needs to be done each and every week.”

That confidence carries over to a matchup against an experienced quarterback this week — Penn State’s Sean Clifford. This will be Iowa’s third meeting against Clifford, who led Penn State to a 17-12 win in Iowa City two years ago.

Clifford ranks third in the Big Ten in passing yards (1,336), passing touchdowns (11) and completion percentage (67.3 percent). His legs may be as dangerous as his arms, too. Clifford is capable of scrambling to pick up first downs, something he did three times in the 2019 matchup between the teams.

“We need to get pressure in his face to get him off his mark,” Hawkeye defensive lineman Logan Lee said. “Number one thing is push the pocket, collapse the pocket and try to get pressure and cause a disruption on the throw.”

Iowa ranks seventh in the conference in team sacks (13) and Penn State ranks sixth in sacks allowed (8).

When Clifford does have a clean pocket, his favorite target is Jahan Dotson.

Dotson has recorded 127 receptions for 2,021 yards in his career, and has caught a touchdown in six consecutive games. The senior has 19 career receiving touchdowns, a program record.

“I’m as impressed with No. 5 as anybody we’ve seen this year,” Ferentz said. “I say that with all due respect, because we’ve played against some really good players so far. But he’s outstanding.

“You just watch him play, there’s no wasted movement. He’s concise. Everything is really sharp. I have to think the pro guys … like him. He’s a really decisive player. He’s a talented player, but he’s a good football player. He plays hard.”

Dotson caught eight passes for 139 yards and a touchdown in Iowa’s win over Penn State last season.

Quarterback sneak university

Petras ran for two touchdowns in Iowa’s Week 5 win over Maryland, with both of them coming via quarterback sneak.

The Hawkeyes have made the play part of their brand — especially with Nate Stanley’s success with it. Petras never ran plays under center in high school, but has become comfortable taking snaps and running a sneak, particularly with an All-American center in front of him.

“[Tyler] Linderbaum and the two guards are usually pretty incredible at wedging that pile,” Petras said. “And if it’s close at all, [Fullback] Monte Pottebaum can come in and push that thing forward. So it’s pretty good.”

If Petras needs an extra push to get the first down or into the end zone, Pottebaum rams into his back to move the pile forward.

“He really should get the dang credit for the QB sneaks,” Petras said of Pottebaum, who ran for his first career rushing touchdown at Maryland. “I’m just kind of like a battering ram, and everyone else is the force. But no, it doesn’t hurt. Especially because it works.

“Whenever we get that call, I think kind of everyone enjoys it, especially when we’re successful on it,” Linderbaum added. “I feel like that’s what Iowa football is all about. Getting down and dirty. Nothing’s better than a QB sneak, right?”