Marshall didn't miss a shot, going 6-for-6 from the field, 3-for-3 from the free-throw line and drained both of his three-point attempts. He has scored in double digits in six straight games dating back to last season and entered the game averaging 16.8 points.
Grambling State (0-3) led briefly in the first period, but Marshall tied it at 4 with a layup, then drained a 3-pointer to give the Bears (3-0) a lead they never relinquished.
Missouri State shot 59.6 percent from the field on 34-of-57 shooting, compared with 38.6 percent for the Tigers on 22-of-57 shooting.
Wisconsin forward Nigel Hayes has withdrawn from the NBA draft and will return to the Badgers for his senior season.
Recruiting reporter Jeff Borzello has gotten grilled for his selections of underachieving and overachieving college basketball programs. He joins Phil Murphy to explain his rankings.
UConn center Amida Brimah and guard Rodney Purvis have withdrawn from the NBA draft and will return to school for their senior season.