Much of the credit goes to the offensive line and its coach, Mac McWhorter, a unit that head coach Bill O'Brien seems particularly fond of.
"They're coached very well," he said. "There's great chemistry with these guys. They get along really well, and they care about each other, and they care about their teammates. They're physical players.
"We told them from Day 1 of training camp that we were going to try to be a physical offense, a north-and-south running team, and they've done a nice job of that."
The line appeared to grow in strength and confidence as Saturday's game wore on. Zwinak, who scored two touchdowns, burst mostly between the tackles. Bill Belton, a 202-pound sophomore from Winslow Township High, returned after missing three games (sprained ankle) and had 65 yards.
"The biggest thing is communication and just making sure we're all on the same page," junior guard John Urschel said. "Honestly, we've got good individual players, and the key is just to make sure that we come together as an offensive line and that we're all on the same page every single play."
O'Brien said he was pleased with the toughness the line showed against an Illinois front four that had been the defense's biggest asset.
The real find in the backfield has been Zwinak, who tore the anterior cruciate ligament in his knee at a practice in October 2010 when he was redshirting and carried the ball just three times last season.
"This is like every kid's dream," he said. ". . . I know where I'm supposed to cut, what I'm looking at, but whatever happens, happens. It's a reaction to whatever the line is doing. They blocked great today."
The running game will have to be even more efficient next Saturday when the Nittany Lions host Northwestern at Beaver Stadium. The Wildcats, who moved into the AP rankings Sunday at No. 24, rolled up a school-record 704 yards on 93 plays and compiled 36 first downs in their 44-29 home win over Indiana.
With numbers like that, the Nittany Lions must find ways to control the football. They held an advantage of almost six minutes in time of possession against Illinois.
The Penn State defense would do well to perform in the same way it did over the weekend, when it stopped the Fighting Illini three times in the red zone, held them to zero or negative yards on five possessions, and kept them without a third-down conversion until late in the third quarter.
Senior linebacker Michael Mauti, who accounted for all three Illinois turnovers with a forced fumble and two interceptions, was named national defensive player of the week Sunday by the Walter Camp Football Foundation.
Contact Joe Juliano at 215-854-4494 or firstname.lastname@example.org, or follow on Twitter @joejulesinq.