The Spartans (28-7) finally put away the pesky No. 16 Blackbirds (25-9) with a 14-4 run midway through the second half.
Michigan State will play Saint Louis in the third round Sunday.
Green added 12 rebounds and 10 assists. The Big Ten’s player of the year also provided some encouraging – and a few choice – words for his teammates in the second half when LIU was giving the Spartans all they could handle.
Jamal Olasewere scored 17 for LIU.
NORTH CAROLINA STATE 79, SAN DIEGO STATE 65
Richard Howell doubled his average, scoring 22 points, and 11th-seeded North Carolina State used its muscle inside and a sticky defense to upset San Diego State in a second-round Midwest Regional game.
The 6-foot-8, 250-pound Howell got the Wolfpack (23-12) off on the right foot with 15 first-half points, carrying them into a showdown with No. 3 seed Georgetown
Lorenzo Brown added 17 points, C.J. Leslie 15 and Scott Wood 10 for the Wolfpack, who are now 12-5 in their first NCAA games.
Jamaal Franklin had 23 points for the Aztecs (26-8).
GEORGETOWN 74, BELMONT 59
Jason Clark scored 21 points, Otto Porter added 16 and Georgetown’s ruthless defense bottled up Belmont’s shooters, advancing the Hoyas after first-game knockouts the past two years.
Henry Sims had 15 points for the third-seeded Hoyas (24-8), who shot 62 percent from the floor.
Belmont (27-8) had its 14-game winning streak stopped and fell to 0-5 in NCAA appearances.
Blake Jenkins scored 17 to lead Belmont, but senior Kerron Johnson, the Bruins’ leading scorer, had just 4 – 10 below his average.
SAINT LOUIS 61, MEMPHIS 54
Kwamain Mitchell scored 22 points, including three big 3-pointers, and Saint Louis (26-7) rode its gritty defense to a victory over Memphis (26-9) in a West Regional second-round game.
Mitchell closed the first half by banking in a 3, then nailed two others to help the ninth-seeded Billikens (26-7) overturn an eight-point second-half deficit. They’ll move on to play the winner of LIU Brooklyn and top-seeded Michigan State on Sunday.