They'll be strong favorites to win their ninth in a row Friday night when they visit the Toronto Raptors, who they've dominated recently.
After starting 4-3, the Heat (12-3) have reeled off eight consecutive victories. They played mediocre defense in their first seven games, surrendering an average of 100.9 points on 47.3 percent shooting.
During the winning streak, those numbers have dropped to 91.9 and 41.5 percent. Miami is also forcing an average of 19.3 turnovers over its last eight games.
The Heat held Cleveland to 34.9 percent shooting in a 95-84 road win on Wednesday - the fifth time in sixth games they've limited an opponent to 92 points or fewer. Cavaliers starters were a combined 10 for 39 (25.6 percent) from the field.
"Our defense has been better, certainly much better from those first few games of the season," coach Erik Spoelstra said. " ... Not only the activity, but the focus and commitment - finishing plays, even on the glass, the way we started the season is not the type of habit we want to create. We know we're going to have to continue to try to get better, there's thing we can clean up ... But the guys have been engaged and we're using our depth and the guys are playing hard."
Miami started off slow offensively, trailing by six after one quarter with James posting just three points in his fifth game as a visitor in Cleveland. He finished with 28 points, eight rebounds and eight assists.
"I didn't feel good early on, but once I got back into the game I started feeling better," said James, who is averaging 27.6 points while hitting 61.4 percent of his field goals during the winning streak. "In the second quarter I got into some good rhythm. We started knocking down some shots and I got some rebounds and steals."
James scored 35 points with eight rebounds and eight assists in a 104-95 win at Toronto on Nov. 5, Miami's sixth straight victory there and 12th straight overall in the series. The Heat haven't dropped a game to the Raptors since Jan. 27, 2010.
Toronto (6-8) occupies first place in the unimpressive Atlantic Division - its four other teams are a combined 19-43. The Raptors would like to protect their home court better after dropping three of four there, including a 102-100 loss Tuesday to a struggling Brooklyn squad that was without Deron Williams and Brook Lopez.
They're averaging 94.5 points in regulation over their last four home contests.
"Big picture long-term, we have to do a better job at home," coach Dwane Casey said. "Our focus is not what it needs to be here at home."
Rudy Gay has struggled of late, averaging 14.7 points on 34.1 percent shooting in his last three games. DeMar DeRozan has elevated his play, however, leading the NBA since Nov. 15 with 28.6 points per game.
Gay was just 3 for 10 for 13 points with four turnovers in the first meeting while DeRozan scored 21 on 8-of-15 shooting.