The Heat matched the fifth-longest winning streak in NBA history despite a sub-par night from LeBron James, who was limited to 15 points on 3-of-11 shooting from the floor.
James, however, provided seven rebounds and seven assists.
The Heat will seek to become just the fourth team in league history to win 20 straight when they face Philadelphia Wednesday.
The Hawks were led by Josh Smith with 15 points and six boards.
Senate Democrats to pull all-nighter on climate change
Susan Sarandon 'very excited' about daughter's pregnancy