George Mason (13-5, 5-1 Colonial Athletic Association) opened the game on an 18-9 run and pushed that advantage to 21, 43-22, en route to a 45-30 halftime lead.
The Patriots led by as many as 24 in the second half before James Madison fought back to within 10, 82-73, with less than two minutes to play.
George Mason held the Dukes to 9 of 31 shooting in the first half and 6 of 21 from 3-point range.
College basketball fans should be excited about next season's Jimmy V Classic, an event that will feature Duke's heralded freshman class.
Jeff Goodman logs all the coaching changes following the 2015-16 college basketball season.
Can Josh Pastner keep top talent in Georgia? Will Tubby Smith change his recruiting philosophy at Memphis? New coaches face some difficult questions.