Paul Pierce had 15 points and 10 assists and Glen "Big Baby" Davis had 18 points and 10 rebounds. Ray Allen scored 18 points and Nate Robinson had 14 for the Celtics (21-4).
Marvin Williams had a season-best 26 points and Jeff Teague scored 18 for the Hawks.
Boston point guard Rajon Rondo missed the game after spraining his left ankle in Wednesday's win at New York. He's expected to be sidelined at least a week. Center Shaquille O'Neal was also out, missing his fourth straight game with a sore right calf.
Boston led by six points entering the final quarter, but the Hawks closed within 77-75 on Teague's one-handed runner in the lane.
The Celtics then scored seven straight points, with Davis and Semih Erden sandwiching baskets around a 3-pointer by Pierce, making it 84-77 with just under eight minutes to play.
Atlanta sliced it to 84-78 on Damien Wilkins' free throw, but Pierce hit two free throws and Robinson nailed a 3, helping Boston pull safely in front. Allen's 3-pointer made it 100-86 with 1:53 left.
The Celtics — behind Allen's 10 points — took a 73-63 lead late in the third quarter. Coming off screens and getting wide-open looks, Allen hit his first three shots of the quarter. But the Hawks stayed close because of some good outside shooting of their own, hitting 65 percent from the field (11-of-17).
Boston led 75-69 entering the final quarter.
Notes
Hawks G Jamal Crawford was sidelined with a sore back. … Boston coach Doc Rivers talked about the team's need to get players back before the game. "If a guy can play, we're throwing him in," he said. Then the Celtics lost guard Von Wafer, who missed the second half with a sore back. It gave them three guards (Rondo and Delonte West, broken wrist) out to go along with three big men (Kendrick Perkins, Shaquille O'Neal and Jermaine O'Neal). … Atlanta's Al Horford and Mike Bibby each were whistled for technicals. … Atlanta's Josh Smith had one point on 0-for-8 shooting. He had only two in Boston's 99-76 road win on Nov. 22. … Red Sox INF Kevin Youkilis was seated courtside.