The Spartans (19-8, 6-6) blew the game open with an 18-0 first-half run. They made 65 percent of their shots in the first 20 minutes and led 44-17 at halftime.
Adam Haluska, the league's leading scorer at 21.2 points per game, had scored 11 points to lead Iowa (15-12, 7-6). He was 3-for-14 from the field and 0-for-6 from 3-point range.
The Hawkeyes shot 25 percent from the field in the first 20 minutes, when the Spartans had one more 3-point basket than Iowa had field goals.
Michigan State avenged a 62-60 loss in Iowa City in the Big Ten opener, as Iowa struggled with seven assists and 17 turnovers.
The Hawkeyes appeared sluggish from the outset, just 42 hours after their snow-postponed win over Northwestern.
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Former Kentucky guard Ed Davender, the only Wildcat with at least 1,500 points and 400 assists, has died. He was 49.
Guard Naz Mitrou-Long, whose 2015-16 season ended in December due to hip problems, has been granted a hardship waiver for the coming season, Iowa State said.
As the Sooners look to life without superstar Buddy Hield and his sidekicks, it's clear their unseasoned players will need to grow up fast.