The Terps' easy and surprising victory came at college basketball's Old Spice Classic in Orlando and gave Coach Gary Williams his 401st victory at the ACC school.
Maryland's lead was just 37-34 at halftime, but when MSU's leading scorer, Raymar Morgan, committed his fourth foul early in the second half, Maryland had no problem breaking down the Spartans' three-guard offense.
Eric Hayes's three-pointer gave Maryland a 46-43 lead, one it never relinquished.
Greivis Vazquez also scored 17 points with six assists.
Hayes and Adrian Bowie scored 13 points apiece, and Bowie added three blocked shots for the Terps (4-0), who next play either Oklahoma State or 10th-ranked Gonzaga.
Travis Walton led Michigan State with 16 points and five rebounds.
Darrell Summers, the only other player in double digits, added 10 points with four rebounds for the Spartans (2-1).