Hawks guard Trae Young takes a 3-pointer over Celtics guard Jaylen Brown to give Atlanta the lead and the win, 119-117, with 2.1 seconds left in Game 5 of the first-round playoff series on Tuesday in Boston. Charles Krupa/Associated Press

BOSTON — Trae Young had 38 points and drained a long go-ahead 3-pointer from beyond the top of the key with 2.8 seconds left to help the Atlanta Hawks cap a late comeback and beat the Boston Celtics 119-117 Tuesday night.

The victory trims Boston’s lead in the first-round playoff series to 3-2 and sends the teams back to Atlanta for Game 6 on Thursday.

John Collins added 22 points for Atlanta, who played without Dejounte Murray, who was suspended for one game for bumping official Gediminas Petraitis with his chest while walking off the court after the end of Game 4.

Jaylen Brown scored 35 points and Jayson Tatum added 19 for the Celtics, who were outscored 37-25 in the fourth quarter.

Derrick White put the Celtics in front 117-116 with 7.3 second remaining, setting up a final possession for the Hawks. The ball went to Young in the backcourt, who dribbled into the front court and knocked down a 29-footer over Brown. The Hawks hit 19 3-pointers in the game.

The Celtics bobbled their initial inbounds pass and had another chance with 0.5 seconds left, but Tatum’s fading 3-point try found only air as time expired.

Brown, who has been recovering from a late-season facial fracture, went unmasked for most of the Celtics’ victory in Game 4, saying he found energy after taking it off during a 31-point scoring night.

He wore it again for Game 5 and maintained the same intensity, leading all scorers with 23 first-half points and connecting on 10 of his first 13 shots.

Atlanta trailed by 13 before trying the game at 111 on a 3-pointer Young.

Boston pushed the ball up the court and got the ball to Robert Williams III, who dropped in a layup. He was fouled but missed his ensuing free throw.

The score was still 113-111 when Young drove and was fouled by Al Horford. Tatum took issue with the call and was whistled for a technical foul. Young hit all three free throws to put the Hawks in front 114-113.

Brown turned it over, then misfired on a driving layup. Atlanta’s next possession ended in a jump ball that was controlled by Boston. Williams scored on a layup to put the Celtics back in the lead with 25 seconds left.

Young was fouled again with 15.8 seconds remaining and connected on two more free throws.

The Celtics called a timeout. The ensuing play wound up with White driving to the basket. He was fouled and went to the line for what proved to be the game-winning free throws.

With Murray out, Young picked up the offensive slack and helped Atlanta keep pace early, scoring nine of Hawks’ first 13 points.

NOTES: Atlanta started collectively better from 3-point range, hitting 6 of 11 in the opening 12 minutes to take a 30-27 lead into the second quarter. But they shot just 3 for 10 from beyond the arc in the second period as Boston nudged in front. … Boston had a two-point jumper by Horford upgraded to a 3 after review with 8:07 left in the second quarter to tie the game at 41. Boston then outscored Atlanta 25-17 the rest of half and led 66-58 at the half.