BOSTON — Philadelphia 76ers center Joel Embiid reveled from home in a wretched Celtics loss, as the Atlanta Hawks' 119-117 win in Game 5 on Tuesday afforded his right knee sprain two more days of rest.

Inside Boston's locker room, Marcus Smart could not find the exit fast enough. Jayson Tatum, the No. 2 seed's superstar answer to Embiid, sat dejected, his knees wrapped in ice, a hand covering his face while he stared blankly at his phone, long after the rest of his teammates had showered, dressed and filtered out.

In the hallways of TD Garden, Celtics executives, staffers and family members were stunned by the defeat, angry even, because they all understood the reverberations of failing to close out their first-round series.

"Gave them life and s***," one said.

"Now they've got to go back to Atlanta," said another.

"I'm not going with them."

This is what Atlanta's Trae Young does to opponents. For all his foibles, the diminutive point guard shoots for their heart, and when he connects, he basks in their suffering. And, man, did he connect on a 30-footer over Jaylen Brown with 2.8 seconds remaining. Young's fifth trey of the night erased Derrick White's go-ahead free throws moments earlier and pulled his seventh-seeded Hawks within 3-2 in this best of seven.

The 3-pointer came 47 minutes and 47 seconds after the first of Young's game-high 38 points — naturally another triple off the opening tip. In between, he played 44 minutes, including the entire second half in the absence of suspended backcourt mate Dejounte Murray, and Atlanta trailed for the vast majority of them.

The Celtics led by as many as 13 points in the fourth quarter and 111-99 with 5:24 left on the clock — and presumably in the series. Young paid no mind. He found Onyeka Okongwu for a layup and his 13th assist of the night. Back-to-back John Collins buckets cut the lead in half, and Young drilled a 27-footer to pull the Hawks within 111-108 at the three-minute mark, quieting the last of the Boston crowd's "overrated" chants.

"When people do that, I think that's just total respect," said Young, who struggled mightily during the first two games in Boston. "They ain't doing that to everybody. You know what I'm saying. I've been in the moment my whole life. That's what I do. I'm not afraid of it. I've worked too hard to be afraid of the moment."

Young tied the game with a 26-footer on the next possession. After a Robert Williams III put-back returned the lead to Boston, Young drew a foul from Al Horford, and Tatum's complaint on the call drew a technical foul. Young made all three free throws for a 114-113 edge and Atlanta's first lead since well before halftime.

"Fourth quarter, close game, being with Trae my whole career, I know what time it is — it's Ice Trae time," said Collins, who added 22 points. "He does his thing. He's clutch, and he wants to be in those moments. He wants the big shot. It's just sort of normal for me to see him go into that mode and do what he does."

Tatum found Williams for an alley-oop and a one-point advantage with 25.6 seconds remaining. Young and White traded free throws, setting the stage for the 30-footer that sent the series back to Atlanta for Game 6.

"Shots started going in," said Young, "and kept going in."

When the buzzer sounded on Tatum's errant response, Young had scored Atlanta's final 14 points and singlehandedly outperformed Boston's vaunted offense by eight points over the game's last five minutes.

"When you give a team life," said Brown, who scored a team-high 35 points, "you leave it up to chance."

As soon as Young returned to the locker room in the aftermath of his winner, he FaceTimed Murray, who will be available on Thursday night.

"I told him to be ready," Young said. "I told him before the game we were going to take care of business so he can play in Atlanta, so I can't wait to see everybody in Atlanta."

Young's heroics punctuated Boston's comedy of errors down the stretch. The Celtics committed four turnovers in those final five minutes. Blake Griffin saw his first playing time of the series in the fourth quarter. First-year coach Joe Mazzulla benched Malcolm Brogdon and replaced White — their third-best player in the series — with Smart, all as Atlanta doubled Tatum and rode athleticism to the comeback. Smart inexplicably fouled Young at midcourt after Boston had regained the lead with 15.8 ticks left, and White's entry pass in the final seconds never found Horford, who had established position on the block.

"We just lost our pace a little bit on the offensive end, partly on me trying to make sure we run a good play," said Mazzulla, who did not call timeout as the lead evaporated. "We talk about playing faster down the stretch, and we lost some of our pace, which allowed them to pressure us and get in the passing lanes."

Two days after Tatum stressed the importance of winning Game 5 and avoiding the prolonged series that contributed to his exhaustion in last season's Finals, he was soaking in the sweat of a familiar subpar effort.

Meanwhile, the rest of the Celtics and their families had cleared the long hallway from media availability to the locker rooms, where a smiling Young strode sipping from a small cup of water. Ice cold, we presume.

"That was loud," he said of the once-raucous arena he had silenced.