Weisman hurt his right ankle on his touchdown, which ended up being his last carry of the afternoon.
On a rainy day at Spartan Stadium, Vandenberg threw an early interception when his pass was tipped by defensive lineman William Gholston and picked off by Denicos Allen.
Michigan State took over at the Iowa 26 and gave the ball to Bell four straight times. His 14-yard touchdown run made it 7-0.
The Hawkeyes trailed 10-0 in the second quarter when Jordan Cotton had a kickoff return for a touchdown nullified by an illegal block. Iowa still ended up with the ball near midfield and drove for a field goal.
Michigan State missed a chance to score in the final seconds of the half because of a farcical miscommunication. Maxwell completed a 19-yard pass to Mumphery to the Iowa 32 with 6 seconds left. The clock stopped momentarily because of the first down, but there was mass confusion among the Spartans, who needed only to stop the clock with a spike and bring their field-goal unit out.
Michigan State eventually got lined up — but Maxwell, the quarterback, was nowhere to be seen. Bell went to the line of scrimmage as if to take the snap himself, and Maxwell finally ran over from the sideline to the backfield, but the clock ran out.
"I was running down and saw the field-goal team running on, so I thought we were going to sneak in a quick field goal," Maxwell said. "So I ran off, and we had half the offense and half the field-goal team."