Cassius Winston scored 19 of his 20 points in the second half and Rocket Watts matched a career high with 21 points, helping No. 24 Michigan State rally to beat No. 18 Iowa 78-70.
The Spartans moved into sole possession of second place in the conference Tuesday night with their third win in four games.
The Hawkeyes slipped to sixth place in the Big Ten, possibly making an impact on their seeding for the conference tournament in two weeks.
Iowa's Luka Garza scored 20, Ryan Kriener had 18 points before fouling out and Connor McCaffery added 11 points.