The Heat led by as many as 36 points in the third period while winning their third straight game.
Miami played on the road for only the ninth time this season, the fewest number of away games for any team in the league.
After taking a 14-point lead in the opening period, Miami saw its advantage cut to three with 8 minutes to go in the half. The Heat then went on a 22-9 run to close out the second quarter and turned the game into a rout in the third.
Jae Crowder had 15 points off the bench to lead the Mavericks.
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