Jeff Teague hit consecutive 3-pointers as the Hawks rallied from a nine-point deficit in the fourth quarter.
But Josh Smith, on an awful night, missed two free throws with just over a minute remaining, and James finished off Atlanta after the teams traded turnovers.
Everyone in the building knew James would shoot, but it didn’t matter.
He muscled away from DeShawn Stevenson, swished a 15-footer and hopped along the sideline in front of the Atlanta crowd. The Heat won without Dwyane Wade, who didn’t play because of a cold.
Chris Bosh led Miami with 24 points. James just missed a triple-double, adding 11 rebounds and nine assists.
Teague paced the Hawks with 20 points.
With the Heat beginning a six-game road trip, Wade came down with a cold and stayed behind at the team hotel.
The Heat didn’t want to take a chance on his condition worsening or spreading to his teammates.
Miami managed just fine without him.
It helped that Smith kept missing for the Hawks, perhaps because he was exhausted from guarding James much of the night.