James added eight rebounds and eight assists against his former team, and Kevin Love fought through back spasms to contribute 28 points.
James added eight rebounds and eight assists against his former team, and Kevin Love fought through back spasms to contribute 28 points and 15 rebounds.
Kyrie Irving scored 23 points as Cleveland notched their third straight victory and their second in a row by 30 points.
Cleveland held the Heat to 34.8 percent shooting from the field -- a season low for a Cavaliers opponent and the Heat's season low.
Cavs coach Tyronn Lue said the defensive contribution of DeAndre Liggins, who has started the past two games in place of J.R. Smith, had been a key piece of the turnaround following the Cavaliers' three-game losing streak.
"He's done a great job for us and he's a big part of this three-game winning streak we have right now," Lue said. "His defense and his deflections, it's contagious. The way he plays and plays hard, guys respect that."
The Heat, hit by Dwyane Wade's departure in free agency and a spate of injuries, are floundering.
They languish in last place in their division, their playoff hopes already looking dim with three quarters of the season remaining.
Miami's Udonis Haslem was a late scratch for personal reasons, which meant there were no Heat players on the floor who played with James prior to his departure from Miami three seasons ago.
"It does feel like a former team, but it's not many ties left besides the coaches," James said. "Without UD here, there's none of the players that I played with, so it doesn't have that feeling like that when you go out there. But it hasn't been like that for me for a little while anyways."
Former Cavs guard Dion Waiters, nursing a torn thigh muscle, was among six Heat players sidelined by injury, and the available players just couldn't keep pace in the second half.
A driving layup by Irving at the third-quarter buzzer stretched Cleveland's lead to 87-69 and coach Tyronn Lue pulled his starters after James passed Elvin Hayes (27,313) for ninth place on the scoring list.
James came into the contest with 27,288 points and needed 26 to move up the list.
"Any time I'm mentioned with any of the greats -- he's one of them -- it's very surreal, and very humbling," James said.