Valentine finished with 15 points and 11 rebounds as the Spartans (17-1, 6-0 Big Ten) reeled off a 10th straight win.
Keith Appling also scored 15 points for MSU.
The Fighting Illini (13-6, 2-4) were paced by Tracy Abrams' 15 points. Rayvonte Rice and Jon Ekey contributed 12 each.
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