The Cavaliers evened their series with the Celtics at a game apiece after blowing out the C's 118-94 in Game Two at TD Garden.
Donovan Mitchell led all scorers with 29 points for the Cavs.
He also collected seven rebounds and dished out a game-high eight assists.
Evan Mobley recorded a double-double with 21 points and 10 rebounds.
Cleveland will look to defend homecourt when the series shifts to Rocket Mortgage FieldHouse for Game Three Saturday night.