Pau Gasol hit the game-winning free throws with six seconds left -- followed by a block on Kyle Korver, preventing a possible overtime session.
The Lakers barely recovered after losing a 21-point lead, Atlanta’s Paul Millsap tying the score at 103 with 35.3 seconds left.
Jordan Hill collected a crucial offensive rebound with 17.9 seconds left, setting up the Lakers' final offensive sequence and Gasol's free throws.
Kyle Korver led all scorers with 22 points on 8-of-10 shooting. The Hawks shot 44.4% from the field with six players in double figures. Al Horford notched a double-double with 12 points and 16 rebounds.
Xavier Henry, making his first start for the Lakers, led the team with 18.
Eleven Lakers played as Coach Mike D'Antoni continued to experiment with his rotation.
The Lakers play next on Tuesday night in Dallas against the Mavericks.
The Hawks briefly closed to within seven points before the Lakers regained composure, extending their lead back to double digits.
Through 36 minutes, the Lakers shot an even 50% from both the field (34-68) and the three-point line (9-18), led by 14 from new starter Xavier Henry.
The Hawks had four scorers in double figures through three quarters, led by 13 from Kyle Korver and Mike Scott.
Pau Gasol notched a double-double in 22 minutes with 13 points and 13 boards.
The Lakers extended their lead over the Hawks to 21 points in the second quarter with 11 different scorers.
Atlanta shot 45.5% from the field.
Both teams took good care of the ball with four turnovers each.
Xavier Henry gave the Lakers' starting lineup a boost, scoring the team's first five points as the Lakers took an 11-point lead after a quarter of play against the Atlanta Hawks.
Nick Young also chipped in five after his demotion to the bench. The Lakers as a team shot 58.3% from the field and 62.5% from three-point range.
The Hawks shot 43.5%, led by Mike Scott off the bench with eight.
Pau Gasol led the Lakers with seven points.
Given how difficult the Lakers' schedule has been this first week, a 2-2 record without Kobe Bryant (Achilles' tendon) would be a strong start to the season.
For a more in-depth breakdown, check out Preview: Lakers vs. Hawks.