Jae'Sean Tate finished with 21 points and 10 rebounds for the Rockets, who fell for the second time in two days and have lost eight straight games.
The Heat can complete the first-round sweep by winning Game Four on Sunday.
Karl Malone, the second highest scorer in NBA history and twice league Most Valuable Player, ended his career Sunday where it all began with the Utah Jazz.
The Detroit Pistons moved into a first-place tie with the Cleveland Cavaliers in the Central Division after a 91-61 romp over the New York Knicks.
Paul Pierce scored 23 points and Ricky Davis added 18 to spark the Boston Celtics to a 100-86 win over the Indiana Pacers.
Kobe Bryant poured in a game-high 31 points to spark the Los Angeles Lakers to a 105-96 win over Minnesota Timberwolves.