The Atlanta Hawks had been here before. In fact, they didn't even have to go back that far to remember the same situation, either.

In Game 5 of their series against the Philadelphia 76ers on Wednesday night, Atlanta was staring at a 26-point deficit as it tried to get the advantage in the Eastern Conference semifinals matchup.

On Monday, Atlanta trailed by as many as 18 before storming back to win. So why couldn't the Hawks do it again?

"There's no quit," Atlanta coach Nate McMillan said after his team's 109-106 win in Philadelphia. "We always talk about playing a 48-minute game. It's a long game. And it took all 48 minutes tonight to get it done."

And as they did in Game 4, the Hawks stormed back for an improbable comeback and took a 3-2 series lead with Game 6 scheduled for Friday at home.

Just how improbable was the victory? According to ESPN Stats & Information research:

• Philadelphia became the only team to lose back-to-back 18-point leads in playoff games in the past 25 seasons.

• The 22-point halftime deficit the Hawks overcame was the third-largest halftime rally in NBA postseason history.

• The 76ers were 165-0 in the past 25 seasons when leading by at least 25 points at any point in the game (regular season or playoffs).

• At one point, Philadelphia had a win probability percentage of 99.7 (the highest it got in Game 4 was 95.5%).

Atlanta trailed by 24 with 2:10 left in the third quarter, but a quick 8-2 run set the tone for the big fourth quarter that followed. In the final quarter, Atlanta outscored Philadelphia 40-19.

Hawks guard Trae Young, who finished with 39 points and went 17-of-19 from the free throw line, said it's "not very difficult" to picture the comeback when down 26 because of the weapons a team like Atlanta possesses.

"We have guys who can make shots and make 3s and really get our offense going. We can put up points really quick," Young said. "I think early on we were missing a lot of open shots and it was one of those first halves again. Hopefully we shoot a lot better at home [on Friday] than we did tonight and the last game. We always have a belief that we're in the game."

Indeed, the Hawks were missing shots in the first half. Atlanta shot only 31% from the field in the first two quarters and went 3-of-12 from 3-point range. The Hawks shot a respectable 47.6% from the field in the third quarter, making half of their 3s, before going a scorching 16-of-22 from the field in the fourth.

For the Hawks duo of Danilo Gallinari and Lou Williams, it was something they'd seen before. Two seasons ago, those two were playing for the Doc Rivers-coached LA Clippers team that overcame a 31-point deficit against the Golden State Warriors in the playoffs -- the largest comeback in NBA postseason history.

"I've done it already when we were down 31. And 26 is better than 31," Gallinari said. "I think you can do it as long as you believe, as long as everyone believes. That's been the main thing since the beginning of the season. When you keep believing and doing your job, amazing things can happen."

Both played big roles in the Hawks' comeback. Gallinari hit a tough fadeaway jumper to put Atlanta up 107-104 in the final minute, while it was Williams who carried them there.

Williams, the 16-year NBA veteran who is from the Atlanta area and got his start playing for Philadelphia in 2005, had 13 of his 15 points in the fourth quarter.

"Just no quit in these guys," McMillan said. "They continued to stay with what we were trying to do. We eventually found a hot hand in Lou and found a rotation that was working for us. We were starting to get stops and just continued to stay with it."

As jubilant as the Hawks were after the victory, the Sixers were distraught and looking for answers. Rivers said he felt like the momentum started to change in the early part of the second half.

"Even though we kept the lead, I think we had six turnovers in our first 10 possessions to start the third quarter. That's why I called the early timeout," Rivers said. "You could see we kind of exhaled, relaxed. The first unit was just good enough and Seth [Curry] carried us in that stretch to keep the lead at 22. Where it could have very easily been at 30 if we don't turn the ball over.

"And then, obviously, you got to take guys out and the second group really struggled tonight in the second half. They were phenomenal in the first half, and then in the second half, they struggled. And then down the stretch. Listen, we scored 19 points and gave up 40. So it's on us. It's on all of us. It's on me. It's on the players. And we have to figure out how to get back up, which we will, and bring this game back here for Game 7."

In the past two postseasons, Rivers-coached teams are 11-5 when having at least a 16-point lead in a playoff game. Every other team in the NBA is 76-3 in that span.

As a part of its strategy to get back in the game, Atlanta went to the "Hack-a-Ben" technique against Sixers point guard Ben Simmons. In the second and fourth quarters, Simmons was intentionally sent to the line eight times -- he went 3-of-8.

It's not the first time the Hawks have picked on Simmons and exploited his free throw shooting this series, either. Simmons shot 61.3% on the season, but he was shooting 67.1% prior to the All-Star break and just 53.3% after.

Following his 4-of-14 performance from the line on Wednesday, Simmons is now shooting 32.8% in the playoffs from the stripe.

When asked about where the nosedive in the later part of the season came from, Simmons said, "No idea. But I need to get it back. It's on me."

Joel Embiid (37 points) and Curry (36 points) carried the load offensively for Philadelphia, but no other player scored more than eight points. Embiid and Curry were the only two players to hit a field goal for the Sixers in the second half and only Simmons added one in the final 31:34.

"We needed to come more together, I think," said the 76ers' Furkan Korkmaz. "This is the playoffs. They are taking advantage of every minute and I think that's the whole point of the game. You got to take care of all the positions. Every position matters. Every point matters."

Tobias Harris, who carried much of the scoring burden in the first four games of the series along with Embiid, said this loss "is going to hurt."

"But tomorrow we have to put it behind us, find a way to get better," said Harris, who finished with four points on 2-of-11 shooting. "Go to Atlanta and get a win. I mean, our backs are against the wall right now and we have to play like it."

When the Sixers make it to Atlanta, they'll be met with a Hawks crowd trying to cheer their team on to what would be only the franchise's second conference finals appearance since 1970.

As the Hawks look toward Game 6, Young was asked if he stopped to think about what the historic comeback meant.

"Not yet. I can't yet," Young said. "We have to finish the job. Maybe after we hopefully close it out next game. Then we can look back at it."