Marshall outshot King 46.7 percent to 37.5 percent from the field, won the rebounding battle 52-38, and dished out 24 total assists as a team.
The Thundering Herd led by five after a tight first half, but progressively built their lead throughout the second, pushing it to double digits on a Cheikh Sane layup with 7:59 left.
The Tornado would mount one final comeback attempt, cutting Marshall's lead to six with 4:38 left on a C.J. Good 3-pointer, but got no closer.
Logan Lyle led King with 20 points and Hunter LeVeau added 12.