Jason Terry was 5-of-7 on 3-pointers and finished with 24 points for Boston, which won its second straight following a five-game losing streak.
Josh Smith led the Hawks with 18 points but shot just 7-of-23 from the floor and 0-for-6 in the second half. Jeff Teague added 17 points and seven assists.
The Celtics, who closed to 1½ games behind the Hawks for the Eastern Conference’s sixth playoff spot, won the season series 3-1.
The Hawks sliced an 11-point deficit to 100-94, but Brandon Bass nailed a baseline jumper and Terry followed with a 3 from the top of the key after a wild scramble for a loose ball that had it slip through the hands of at least four players. Green then nailed a jumper, making it 107-94 with 5:08 left.
The Hawks never threatened the rest of the way.
Boston, which led by 10 at halftime, pushed it to 83-68 on Green’s 3-pointer from the right corner midway through the third and benefited from a poor shooting quarter by Atlanta’s Smith.
The Celtics owned a 92-80 advantage after three. Smith was 0-for-6 from the field, missing five jumpers and came up short on a drive. He also got a technical.
Pierce was close to a triple-double after three quarters, collecting 16 points, 10 assists and seven rebounds.
Terry hit consecutive 3s just 32 seconds apart midway into the second, triggering Boston’s 25-8 run. He made four in the spree and Pierce added one, helping the Celtics to a 66-56 halftime edge.
Jordan Crawford hit a buzzer-beating 3 from directly in front of the Celtics’ bench to give Boston a 32-30 edge after one. The lead flip-flopped nine times in the opening quarter.
NOTES: Pierce fell to the floor hard early in the third quarter and limped to the bench, favoring his left leg, but returned after a timeout. ... Hawks F/C Al Horford missed the game due to an illness. ... Celtics coach Doc Rivers said before the game that the timetable for F/C Kevin Garnett’s return remained the same. “I think it’s still two weeks,” he said. “I don’t think it’ll be any longer than that. But if it’s two and a half, I don’t want to you to call me a liar or anything like that.” Garnett missed his fourth straight with what the team called “left ankle inflammation.” ... Boston G Courtney Lee returned after missing three games with a sprained left ankle. “I worked out (Thursday) and felt good,” he said before the game. “Then at shootaround (Friday morning) I felt good and decided to give it a go.” ... Hawks G John Jenkins left the game with a concussion and the first half and didn’t return. ... Boston G Rajon Rondo, out for the season after right knee surgery, was on the bench.