EAST LANSING, Mich. -- Denard Robinson moved backward, with Michigan State defensive end Marcus Rush closing in on him.

Robinson released the ball. Rush continued and hit him, then pulled him down to the ground. Robinson's pass fell incomplete, but Rush was flagged for a personal foul. The play sent Robinson to the sidelines, and he did not return.

Was it a dirty play?

"Did the referee call it?" Robinson asked after the game.

Denard Robinson leaves the field after a fourth-quarter, late-hit personal foul on Michigan State. AP Photo/Bill Fundaro

Yes, he called Rush for roughing the passer. In all, the Spartans were flagged for six personal fouls, accounting for almost half of their 13 penalties for 124 yards Saturday.

Robinson, though, stopped short of calling Michigan State dirty.

"They were playing football," he said. "It's a dirty game."

Just a little bit more so Saturday at Spartan Stadium. Beyond the Robinson-tossing committed by Rush, receiver Martavious Odoms was tackled by his dreadlocks -- a personal foul. William Gholston was called for two personal fouls, one in which he twisted Robinson's facemask after Robinson had been tackled to the ground and one in which he appeared to throw a punch at Wolverines offensive tackle Taylor Lewan.

It was somewhat similar to a jab that got former Wolverines linebacker Jonas Mouton a one-game suspension in 2009.

Michigan coach Brady Hoke said he didn't see the punch.

There were also late hits and an overall sense of Michigan State trying to make something clear to Michigan -- that the Spartans were tougher, no matter what.

So was it dirty?

"Definitely. Definitely," Michigan State defensive tackle Jerel Worthy said with a small smile on his face. "Any rivalry you have like that, there's going to be little cheap shots and stuff like that. But you've got to just play through it.

"It's football, at the end of the day, man on man. You've got to overcome it."

Michigan's players used a similar explanation, saying it was "football."

But they also admitted they were expecting something close to what happened inside Spartan Stadium, where Robinson walked off the field with a healthy swatch of green all over his white Michigan road legacy jersey.

Most of Michigan's players looked like that. They were pushed around and beaten up by Michigan State.

"I've played in this game before," safety Jordan Kovacs said. "So I know how it goes."

This, though, had an added sense of anger and intensity. After the game, Michigan and Michigan State didn't exchange the usual post-game handshakes.

And as if to add insult to already being beaten, as Michigan State's Isaiah Lewis was finishing off a 39-yard interception return for a touchdown in the fourth quarter Saturday, he briefly held the ball out to taunt Robinson before crossing the goal line.

Lewis wasn't flagged, but had he been, the touchdown would have been nullified under new NCAA rules instituted this season. But it was just another way the Spartans expressed themselves against the Wolverines. Yet after, Worthy said the Spartans were trying -- at least a little bit -- to avoid penalties.

That was their least effective performance of the day.

"You always want to stay away from as many penalties as possible," Worthy said. "But at the same time, you want the quarterback to feel your presence. I think some of those calls were just a little over the top, but at the same time you have to protect the quarterbacks in this league.

"That's what they were trying to do."

Hoke, though, at least said he didn't feel Michigan State played dirty.

"I don't know how they played dirty. They had some personal fouls on late hits on the quarterback," Hoke said. "But you can get those all the time."

On Saturday, it seemed as if Michigan State got as many of those as possible. Whether overzealousness or strategy, it sure seemed to knock Michigan and its quarterbacks for a loop.

Michael Rothstein covers University of Michigan sports for WolverineNation. He can be reached at michaelrothsteinespn@gmail.com or on Twitter @mikerothstein.