Jeff Green had 16 points and Jared Sullinger scored 15 points and grabbed nine rebounds for the Celtics .
Al Horford led the Hawks with 18 points and seven rebounds, and Jeff Teague had 13 points and 10 assists. Atlanta had won four of five games before losing for only the second time this season at home.
The Celtics outrebounded the Hawks 47-38 and held them to 38.7 percent shooting.
Trailing 85-84 with 3:17 to play, the Celtics scored seven in a row to take a 91-85 lead with 46 seconds to play.
Jordan Crawford scored five points during the run, which came during a quarter in which the Celtics outscored the Hawks 30-13.
The Hawks broke open a tight game by closing out the third quarter with a 17-5 run that gave them a 74-64 lead.
Included in that run was a flagrant foul on Sullinger that resulted in a three-point play for the Hawks. Teague had six points and an assist to spark the Hawks, while the Celtics floundered on offense, missing six of their final seven field goal attempts in the quarter.
It appeared as if a grueling stretch for the Celtics was catching up to them, as they were playing their fourth game in five nights in four different cities. Early in the fourth, however, the Celtics put together a 10-0 run as they snapped a six-game losing skid.
Avery Bradley had 12 points and five rebounds for the Celtics and limited Hawks’ Kyle Korver to just nine points. Vitor Faverani chipped in 11 points off the bench.
The Hawks fell into an early 11-5 hole as the Celtics shot 5 for 5 on their first five possessions. Boston cooled after that, but still emerged from the first quarter with a 25-24 lead after shooting 52.4 percent from the floor.
The highlight of the first half came courtesy of Paul Milsap, who drove the baseline and threw down a powerful slam over the 6-foot-11 Faverani.
The dunk gave the Hawks a 40-36 lead and drew a roar from the Philips Arena crowd. Despite just three points from Teague, Atlanta’s leading scorer for the season, the Hawks took a 53-49 halftime lead.
NOTES: Hawks guard Kyle Korver hit a three-pointer in the first quarter, giving him 87 straight games with a three. He is two games shy of Dana Barros’ NBA record of 89 in a row. … Celtics rookie center Kelly Olynyk, who has started six games and is averaging 7.5 points, did not make the trip to Atlanta due to a sprained ankle. He will miss at least two weeks. … This was Boston’s second win over a team with a winning record. The Celtics beat the Heat earlier this season, also on the road.