BOSTON (AP) — His team trailing by a point and its season on the brink, Hawks star Trae Young got all the encouragement he needed in the huddle during his team’s timeout.

“I just had to trust in what I’ve done my whole life and shoot it with confidence,” Young said.

He did, and kept Atlanta’s season alive.

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 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 Thursday.

Young had 16 points in a frenetic fourth quarter, getting support from his teammates who collectively knocked down a series-best 19 3-pointers.

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

With Murray out, Young picked up the offensive slack and helped Atlanta keep pace early, scoring nine of Hawks’ first 13 points. By the time the final quarter arrived, Collins got a sense of familiarity watching his teammate.

“I know what time it is. It’s Ice Trae time. He’s clutch. He wants to be in that moment. He wants the big shot,” Collins said. “It’s what he does.”

Jaylen Brown scored 35 points and Jayson Tatum added 19 for the Celtics, who were outscored 37-25 in the fourth quarter. It came after Boston had dominated for three quarters. For the game the Celtics held a 60-38 scoring edge in the paint and 24-8 in transition.

A sloppy finish made it all for not.

“We had some boneheaded plays, some fouls. Gave them some opportunities to get going,” Brown said. “We just gotta finish the game.”

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 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.

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

As the Hawks began to mount their run, fans inside TD Garden began peppering him with expletive-laced chants.

“When people do that I think that’s just total respect. I mean, they aren’t doing that to everybody,” he said.

Boston pushed the ball up the court and got the ball to Robert Williams, 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 appeared to be the game-winning free throws.

Young had other plans.

“You can tell, you look in his eyes and there was a calm,” Hawks coach Quin Snyder said. “Sometimes that happens in the middle of a storm.”

MR. 4TH QUARTER

Young now has 60 fourth-quarter points in the series.

TIP-INS

Hawks: 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.

Celtics: 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.