Isaiah Thomas led the way with 25 points and eight assists. Avery Bradley added 18 points. Jae Crowder, Kelly Olynyk, Marcus Smart, and Tyler Zeller also finished in double figures for the Celtics.
Goran Dragic had a huge game in a losing effort for the Heat. Dragic scored 27 points and dished out 17 assists.
The Celtics have now won four straight road games. They will host the Pistons on Wednesday night.