The Celtics outscored the Head 31-12 in the third quarter and held the Heat to just 26 percent shooting for the quarter. Miami scored just 28 points total in the second half.
Rajon Rondo was able to pick up a triple-double, scoring 16 points, dishing out 14 assits and pulling down 11 rebounds. Paul Pierce led all Boston scorers with 23 points.
LeBron James scored 23 points on the afternoon, but received little help from his teammates. Dwyane Wade added 15 points but it was not nearly enough.
The Heat will return to action at home Tuesday when they play the Philadelphia 76ers.