James (10-16) and Wade (11-13) made 21 of 29 shots for Miami, which shot 58 percent as a team. Chris Bosh had 14 points and 10 rebounds and Norris Cole scored 10 for the Heat, who handed the Hawks just their second loss in 11 games.
Josh Smith scored 22 points and Al Horford finished with 20 points and 11 rebounds for Atlanta, which briefly held the lead midway through the third quarter before the Heat got rolling and moved 1 games ahead of the Hawks in the Southeast Division.
Atlanta has dropped both games against Miami this season and is 1-7 against the Heat since March 2011.
A big third-quarter run put the Heat in control, and one of James’ best dunks this season helped seal it in the fourth. Cole took a pass from Ray Allen, dribbled once and nonchalantly flipped the ball toward the rim.
James did the rest.
James leaped _ the top of his fingers stretched easily more than a foot above the basket _ for a slam with 9:51 left, and the Heat weren’t threatened in the final minutes.
The Heat came into Monday night talking about how this particular game was significant for many reasons, foremost among them the Hawks’ position in the Southeast Division.
And while it’s way too early to take more than a passing interest in the standings, Miami had taken notice of Atlanta’s early success.
“We’ve been watching,” Heat coach Erik Spoelstra said.
The up-close-and-personal view wasn’t a surprise, then.
Miami led 56-54 at intermission, a well-played half where neither team led by more than five points. The Heat shot 64 percent from the field in the opening two quarters, 50 percent from 3-point range _ but a mere 44 percent from the line, part of the reason why the margin was only two points at the break.
James finished each of the first two quarters with a flurry, first going 1-on-4 for a driving layup to give Miami a 28-26 lead, then blowing past Horford for a layup-and-foul and putting the Heat up two with 14.6 seconds left in the half.
The Hawks were helped mightily by a friend of Heat opponents of late, the 3-pointer. Atlanta made seven from beyond the arc in the half, and through three quarters, Smith was 4 for 4 _ already matching his career-best single-game total from long range.
But in the third, Miami began to flex its muscles.
Jeff Teague made a 3-pointer midway through the third to give Atlanta a 65-63 lead, but after that, Miami took off running.
A 17-4 run was the difference maker, turning a two-point deficit into an 11-point lead with 1:24 remaining in the third. Wade got it started with a jumper, and he wound up with eight during the burst, including a layup off a perfect pass by James from the right side of the lane. Shane Battier made two 3-pointers in the run, including the shot that ended it, and Miami’s margin was suddenly 80-69.