Ray Allen led the way for Heat with 23 points, while LeBron James added 22 and Chris Bosh had 16 points and 14 rebounds.
Allen also sunk five three-pointers, which gave him a record 322 in post-season play.
Carlos Boozer's 22 points and 16 rebounds gave the Chicago Bulls a hard-fought 79-76 win over the Brooklyn Nets and edged them into a 2-1 series lead.
Luol Deng added 21 points and 10 boards for the Bulls, while Brook Lopez paced the Nets with 22 points.
The Los Angeles Clippers' post-season charge stalled as they lost 94-82 to the Memphis Grizzlies, who pulled back to 2-1 in their series.
Zach Randolph led the way for the Grizzlies with 27 points and 11 rebounds.