With the win, the Griffins take a 2-1 lead in the best-of-seven North Division series. Game 4 goes Wednesday in Grand Rapids, Mich.
Matt Hussey scored in regulation for Grand Rapids, with Jakub Kindl getting the assist.
Brendan Brooks countered for Manitoba.
Jimmy Howard made 24 saves from 25 shots for the Griffins, while Drew MacIntyre stopped 34 of 36 shots for the Moose.