Bosh rebounded a missed 3-pointer by the Mavericks and got the ball to Wade, who had a perfect alley-oop pass to James, who caught the ball in midair near the rim and slammed it through with both hands.
After another missed 3 by Dallas later in the first quarter, Wade grabbed the rebound under the basket and then threw a football-like pass the length of the court to James. Even with Darren Collison and Vince Carter fronting him, James leaped and reached over to grab the ball, then finished with a layup to make it 27-13.
Dallas pulled to 36-33 after Dominique Jones had consecutive assists to rookies, a 3-pointer by Crowder and a reverse layup by Bernard James.
But Miami then responded with a 16-4 run.
Miami stretched the lead to 91-55, its largest of the season, when Shane Battier made a 3-pointer with 1:21 left in the third quarter.
Nowtizki practiced for the first time Wednesday, and had an individual workout Thursday. It's still unclear when he will make his season debut, but got a huge cheer when he was shown on the video screen during a timeout.
Collison, who lost the job as the starting point guard when the Mavericks signed Fisher on Nov. 29, was back in the starting lineup and had 11 points.
Fisher was hurt in the first quarter of a win over Philadelphia on Tuesday night. He will skip a two-game trip for games at Memphis on Friday night and San Antonio on Sunday. The team said there is no timetable for the 38-year-old Fisher's return and that he would be re-evaluated next week.
NOTES: Mavs guard O.J. Mayo made only three of 14 shots for eight points before facing his former team on Friday night in Memphis. ... The Heat's largest lead this season before Thursday night had been against Washington last week, when they led by 35 points in the fourth quarter. ... Heisman Trophy winner Johnny Manziel, the freshman quarterback from Texas A&M, was sitting courtside early in the second half. He watched Philadelphia at Houston on Wednesday night. ... When play resumed after a timeout with about 7 minutes left, many fans were watching a fight in the stands instead of the game.