Harris, the former Mr. Basketball from Hamilton Southeastern, scored 24 points as No. 3 Michigan State held on for an 71-66 victory over Indiana at the Breslin Center.
Harris scored 26 points the first time the teams played and 24 on Tuesday night. He had 19 of his points in the second half.
Indiana led by one at the half and by as many as five points at 46-41 with 11:56 to play following a drive to the basket by Troy Williams.
But Michigan State answered with an 11-2 run and never trailed again. The lead got as high as 10 at 62-52 before IU rallied to cut the lead to three a couple of times in the closing seconds.
Michigan State played without Adrein Payne for the fourth game in a row. He is out with an ankle injury. IU played without senior forward Will Sheehey who also missed the game with an ankle injury.
The game featured the return to game action for Jeremy Hollowell who had missed three games in a row for a coach's decision. Hollowell had eight points.
Indiana (12-7, 2-4 Big Ten) had done a better job recently in the turnover department had 18 miscues Tuesday night against Michigan State.
Follow Terry Hutchens at Twitter.com/Foxsportshutch