Taurean Prince had 33 points and Damion Lee added 14 points to lead the Hawks, who won their second straight game.

Jayson Tatum had 19 points to lead the Celtics, who fell for just the third time in their last 10 games despite the loss of Kyrie Irving for the season.

Dedmon hit a 3-pointer with 1:31 left in the game to put Atlanta up 2, and after Boston's Jonathan Gibson tied the game with a jumper, the Hawks reeled off six straight points to put away the Celtics.

Deandre Bembry and Isaiah Taylor added 13 for the Hawks, who shot 50 percent from the field two days after scoring a surprising 103-97 win at the Washington Wizards.

Greg Monroe had 17 points and Semi Ojeleye added 13 points off the bench for the Celtics. Jaylen Brown had 12 points and Terry Rozier added 10 points for Boston.

Boston jumped to a 14-5 lead halfway through the first quarter on a Brown and-1 layup, and led by as much as 12 in the quarter, before going into the second up 31-24.

Atlanta trimmed the lead to four midway through the second after a Prince 3-pointer, but the Celtics built back up a double-digit buffer and went into the half up 58-49. Al Horford had 14 points at the half to lead Boston, and Tatum and Brown each had nine, as the Celtics shot 54 percent from the field and 40 percent from behind the arc and had 18 assists and just four turnovers.

Horford scored just two points in the second half.

Prince had 15 points on 6-for-7 shooting at the half and Bembry added nine for the Hawks.

The Celtics head to play the slumping Wizards on Tuesday before returning to TD Garden to host Brooklyn on Wednesday to wrap up the regular season. The Hawks end their regular season Tuesday at home against the Philadelphia 76ers.

--Field Level Media