Adreian Payne (14 points, 10 rebounds) and Derrick Nix (13, eight) also played big roles for the Spartans (27-8), who now go on to play the winner of Sunday's contest between Duke and Creighton in the Midwest Region.
With the triumph, Michigan State gained its fifth Sweet 16 appearance in the last six seasons.
The Tigers (31-5) were led by Geron Johnson with 16 points.
Joe Jackson also reached double figures with 12 for Memphis, which had defeated Saint Mary's Friday for its first NCAA Tournament victory since 2009.
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