Melvin Ejim scored 22 points and Iowa State beat No. 7 Michigan 77-70 Sunday, spoiling Wolverines star Mitch McGary's season debut.
Naz Long added 16 for the Cyclones (3-0), who held McGary to just one point in the second half while notching one of their biggest wins under coach Fred Hoiberg.
McGary, a preseason first-team All-American who missed two games with a lower back injury, finished with nine points and six rebounds.
Nik Stauskas led Michigan (2-1) with 20 points and Derrick Walton Jr. had 13.
Glenn Robinson III was held to 12 points on 4 of 14 shooting.
Ejim, who also played for the first time after missing two games with a hyperextended left knee, added nine rebounds as Iowa State closed the game on a 23-10 run.