ATLANTA -- It was simply time for something to click.
After they were hurt by the last six minutes of Game 5 on Tuesday, the Boston Celtics admitted they played that same end-of-game stretch in Thursday's Game 6 against the Atlanta Hawks with added urgency and focus, leading to a win that pushed them into the next round of the playoffs.
Effective defense and timely 3s from a host of Celtics in the closing moments helped Boston pull out a 128-120 win over the Hawks at State Farm Arena. The Celtics advanced to the Eastern Conference semifinals for a matchup with the Philadelphia 76ers, who swept the Brooklyn Nets in their first-round series.
"We know they're going to bring the fight," Celtics wing Jaylen Brown said. "Philly is a tough environment to win. Their crowd gets involved in the game. It's going to be fun."
Game 1 of the semifinals is Monday in Boston.
So how do the Celtics explain the way they closed out the Hawks to advance?
"Winning time, I guess," Brown said. "Adrenaline, just that will and perseverance to finish the game. It was close and both teams was exchanging blows, we were both tired.
"And we didn't want to be the team going back home with an 'L.' So we just found a way to win."
A Celtics loss would have meant a Game 7 at TD Garden on Saturday.
But that game won't be happening thanks largely to the late Boston rally started by Brown, himself an Atlanta-area native.
With 4:50 remaining, he buried a 25-foot 3-pointer to get the Celtics going. Across the next two minutes, Al Horford and Jayson Tatum knocked down their own 3s for the Celtics. All three long-range shots went unanswered by the Hawks.
Right after Horford's shot -- which gave Boston a 116-113 lead it didn't look back from -- the five-time All-Star and former Hawks first-round pick turned around and briefly exchanged words with a fan sitting courtside.
"I appreciated it because he got me going," Horford said. "He said some stuff there that I wasn't very pleased with and I took it to heart, and I was able to hit that shot. I appreciate him for talking trash to me.
"Some people you can talk trash to, but you talk to me, it's probably not good for you."
Boston outscored Atlanta 18-8 in the final six minutes, one game after being outscored by the Hawks 23-8 in the same stretch of Atlanta's Game 5 win in Boston. Celtics coach Joe Mazzulla took the blame for his team fading in the previous game.
"Our pace on the offensive end last game, because of me and my playcalling, we played slow," Mazzulla said. "This game I learned from that and we were very proactive."
Describing that slower late-game showing as "helter-skelter," Mazzulla said that in Game 6, his players got space from each other and into their offensive sets more quickly.
"At the end of games, when you can put pressure on defenses just by playing with a sense of pace, it can really help you," Mazzulla said.
Added Horford: "[Thursday] there was that sense of urgency. We understood how important it was to not extend the series, to get the job done."
Brown finished with 32 points, while Tatum had 30. They became the second duo in Celtics history to each score 30-plus points in the same game multiple times in a playoff series, joining Larry Bird and Kevin McHale, who did it against the Milwaukee Bucks in the 1987 Eastern Conference semifinals.
The Celtics didn't have the cleanest start offensively Thursday. They missed 14 shots in the paint in the first half, their second-highest number of missed close-range shots in a first half this season.
Despite those early close misses, the Celtics outscored the Hawks in the paint 54-50.
For the Hawks, Trae Young picked right up where he left off in Game 5. Following up his 38-point performance in Boston that included the game-winning 30-foot dagger, he had 30 points in Game 6. Most of them came in the first half. Across the final 24 minutes, Young was held to a 1-for-8 showing from the field when his shots were contested.
It wasn't until nearly three minutes into the start of the third quarter that Hawks guard Dejounte Murray finally scored his first points on a midrange jumper. Although he was scoreless through halftime, Murray was still productive for Atlanta on the offensive end. The Hawks went 7-for-9 off his passes across the first two quarters.
The All-Star was back in the Hawks' starting lineup after missing Game 5 due to a one-game suspension for making contact with and being verbally abusive to an official. At the end of Game 4, a Hawks loss, Murray bumped referee Gediminas Petraitis as he walked off the floor.
When he addressed the incident two days later, Murray said "a lot" led up to the bump, including a history of feeling disrespected by the official in the years before Murray was traded to the Hawks from San Antonio.
Atlanta's night started by spotting the Celtics nine unanswered points, part of a 12-2 Boston run that prompted a quick timeout from Hawks coach Quin Snyder less than three minutes into the game.
With the loss, Atlanta's season ends. The Hawks went 41-41 during the regular season and blew out the Miami Heat in an Eastern Conference play-in game to secure the No. 7 seed. Atlanta also finished the year going 14-18 in games coached by Snyder, including the postseason.
Still, the Celtics repeatedly credited the Hawks for providing them a serious challenge in this opening series.
"I know the narrative: We were supposed to sweep them, it was supposed to be a cakewalk," Tatum said. "They really tested us, coming in here in this environment, and they had the utmost confidence in this game, and you could see it.
"The way they played, the shots they were hitting. The crowd was into it. It was a fun game to be a part of."
Brown believes battling with Atlanta will help his team as it advances to play Philadelphia.
"It's going to be another test -- again," Brown said. "We're going to have to be ready to fight -- again. And I'm up for it and I can't wait."