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.