Schroder hit a straightaway 3 to make it 116-107 with 2:07 remaining before Thomas’ corner 3 with 55.3 seconds to go cut the lead to five. The Celtics didn’t get any closer the rest of the way.
Boston fell 1 1/2 games behind Cleveland for the East lead, but is still two games ahead of third-place Toronto. Fifth-place Atlanta, which led by 20 in the third, moved one game ahead of Milwaukee. The regular season ends next week.
One night after losing by 23 at home to the defending champion Cavaliers, Boston allowed 71 points in the first half and trailed by 16 at halftime.
The Celtics were sluggish defensively and looked tired during much of the night on Atlanta’s end, getting outrebounded 52-38 and getting called for too many fouls underneath.
The Hawks used a 12-0 run to take a 14-point lead in the final minute of the first. After Boston pulled within one early in the second, Atlanta pushed the lead to 16 on putback jams by Prince and Millsap in the closing seconds of the second.
Boston cut the lead to 10 on Smart’s 3 at the third-quarter buzzer.
The Hawks improved to 32-7 overall, 17-2 at home, when entering the fourth with a lead.
ON THE MEND, ON THE FLOOR
Millsap didn’t start for the second straight game as Hawks coach Mike Budenholzer works him back from a sore left knee. The four-time All-Star won’t play Friday at Cleveland, missing his ninth game in the last 11.
NOT WELCOME HOME
Al Horford, in his second game back in Atlanta after spending his first nine seasons with the Hawks, was whistled five times by the middle of the third and went to bench with just two points, two rebounds and three assists. He finished with four points on 1-for-7 shooting. Horford was a classy citizen and tireless worker on the court, but fans, still upset that he left as a free agent, again booed him every time he touched the ball.
Dwight Howard‘s streak of double-doubles ended at 10 games, his longest since last season with Houston and the longest Hawks streak since Kevin Willis had 21 straight in 1991-92.