Dwyane Wade produced game highs of 32 points and five steals to spark the Heat, who won two NBA titles and reached four consecutive NBA Finals before James left last July to return to his home-region club.
James scored 26 points to lead the Cavaliers, but they were beaten just as in his first return to Miami for a game, a 101-91 Heat triumph last December 25.
Wade and James shared an embrace in the seconds after the final buzzer, following which Wade said the Heat relish beating the Cavaliers in a special way.
“We do. They are one of the better teams in the NBA,” Wade said. “We know when we play the way we played tonight, we can beat anybody. It’s about getting to that game consistency. We haven’t played that way as much as we did today.”
Slovenian guard Goran Dragic added 20 points and nine assists for the Heat while Hassan Whiteside and reserve Mario Chalmers each scored 16 points, Whiteside also contributing a game-high 11 rebounds.
The Heat shot 55 percent from the floor in improving to 30-36, matching Boston and Indiana for the last two playoff berths in the Eastern Conference with 16 games remaining.
“For this team right here, it’s about fighting for the playoffs, so we needed this win,” Wade said.
Kyrie Irving added 21 points and a team-high six assists for the Cavaliers, who were playing without star big man Kevin Love, who was rested by Cleveland coach Dave Blatt.
James had treatment on his right knee before the game, having tweaked it in a Sunday triumph at Orlando.
Miami’s 56-38 half-time lead marked the largest half-time deficit of the season for the Cavaliers, who shot only 38 percent from the court for the game.