Trailing from tip-off until late in the third quarter, Miami stepped up their game late to overcome the Nets (11-5) with Dwyane Wade scoring 34 points while LeBron James added 21.
It is the 12th consecutive win for Miami over the Nets. The Nets had seven players score in double figures, led by Andray Blatche's 20, but failed to keep pace with the Heat's late charge.
The Heat top the Eastern Conference with a 12-3 record and improved to 8-0 at home for the first time, having scored more than 100 points in all eight victories.
Six of the Heat's previous wins this season have come with fourth-quarter fightbacks but Miami made their move earlier in Saturday's game.
"We had an honest talk with ourselves at half-time and we corrected a lot of mistakes," Heat center Chris Bosh said. "We don't really get too rattled if teams jump out on us."
Bosh rejected suggestions the side was falling into the habit of starting slow.
"I don't think it's a habit. It's just playing a game," he said. "Every game is different. Some games we're going to be ahead, some games we are going to be down.
"The most important thing to us is consistency. We need to have a more consistent effort on defence and I think today was a good start to what we are trying to do.
"We know we are going to play better on the defensive end and can pace ourselves on offence."