Chris Bosh (15 points) and Mario Chalmers (14) also reached double figures for the Heat, who went on a 12-4 run early in the second period for a 10-point cushion and maintained the upper hand the rest of the way.
Chris Anderson came off the bench to supply nine points and nine rebounds for Miami.
The Heat, who shot 54.5 percent from the floor, will attempt to establish a commanding 3-1 series lead in Tuesday's Game 4 at Indianapolis.
George Hill contributed 19 points for the losers.
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