LeBron James had 32 points, 13 rebounds and three blocked shots to lead host Miami past Boston in the opening contest of the Eastern Conference finals.
Dwyane Wade added 22 points and seven assists and Shane Battier had 10 points and 10 rebounds for Miami, which began pulling away in the third quarter.
Kevin Garnett had 23 points and 10 rebounds and Rajon Rondo had 16 points, nine rebounds and seven assists for Boston.
Game 2 is Wednesday in Miami.
The contest was tied at 50 early in the third quarter until Battier drained a go-ahead with 8:30 left. The basket started a 12-4 run that saw Miami take an eight-point lead.
Paul Pierce pulled Boston within 62-58 with 4:35 left before the Heat rolled off eight straight points and secured a 70-58 lead on a basket by Mario Chalmers.
A layup by James increased Miami’s lead to 78-61 with 9:48 to play.
Pierce scored 12 points but hit just 5 of 18 shots.
Miami had a 48-33 rebounding edge and blocked 11 Boston shots.
The Heat led by as many 11 points in the second quarter but the contest was tied at 46 at halftime. James had 13 points in the opening quarter as Miami jumped out to a 21-11 lead. Boston hit just five of 20 shots in the first stanza and shot 39.5 percent for the game.
GAME NOTEBOOK: James had 11 20-point outings and four double-doubles in 12 postseason games. … Boston was called for four technical fouls – Rondo, guard Ray Allen and coach Doc Rivers were flagged while another was issued for a delay of game warning. … Officials overturned a first-half basket by Miami’s Joel Anthony after conducting a video review. … Boston was just 11 of 21 from the free-throw line and Allen missed four free throws in the first half. It was the first time he had missed four foul shots in a game since Dec. 26, 2006 when he was a member of the Seattle SuperSonics.