MIAMI — The Boston Celtics easily could have folded.

In the opening minutes of the third quarter, they got three stops on the same possession, and each time the ball found the Miami Heat again. Max Strus turned the fourth attempt into a 3-pointer and a 9-point lead. If ever there were a time for Boston to quit, trailing the Eastern Conference finals 3-0, that was the moment.

Instead, back-to-back Jayson Tatum 3s — the first 6 of his 14 points in the third — ignited an 18-0 run that propelled the Celtics to a 116-99 win, extending their season for another game in Boston on Thursday.

"It could have went either way. We could have separated or brought us together, and we settled in, and we just started making plays," said Tatum, who scored a game-high 33 points. "Obviously, shots were falling, things like that, but we were just playing the right way — getting stops, moving the ball. We played well."

The 48 hours after a third straight loss to open the series against the eight seed posed the greatest threat to the makeup of a team that reached the 2022 NBA Finals and entered this season as title favorites. Calls came from everywhere to end a partnership between Tatum and Jaylen Brown that has almost guaranteed them a spot in the league's final four each year they are healthy. Separate reports suggested, "This Celtics team feels like a group that’s tired of fake liking each other," and, "This locker room never got over Ime Udoka's dismissal as head coach. These players did not accept the organization's reasoning for doing it."

As the outside noise reached a deafening tone, the Celtics called a team meeting on Monday night in Miami, where players challenged each other not to let Jimmy Butler and the Heat embarrass them again.

"Obviously, we underperformed in the last three games, and you start to hear all these stories come out about X, Y and Z, who knows where it actually comes from — 99 percent of them is not true at all," Brown said after Tuesday's win. "We wanted to stay together, and I think that was the emphasis last night before we played today, making sure we were on the same page. We didn't want to come out and lay an egg. We wanted to come out and play together, trust each other, play some defense, have some pride about yourself and find a way to win a game. We're all more than capable of doing it. So, tonight we got it done."

"Everybody was in good spirits, everybody was upbeat, and as cliché as it sounds, we just tried to take it one game at a time," added Tatum. "We tried to break it down. We didn't play well the first three games. We didn't deserve to win, but we didn't want that to define us or define the season. We've still got a long uphill battle to go, but tonight was a good start. Just to try to carry this momentum towards Thursday."

The Celtics arrived to their Game 4 shootaround echoing the sentiments of former Boston Red Sox player Kevin Millar before their comeback from a 3-0 deficit in the 2004 American League Championship Series.

"Don't let us get one," said Marcus Smart.

"Don’t let us win tonight," added Brown.

It was not lost on anyone that the television cameras found former New York Yankees Derek Jeter and Alex Rodriguez — victims of that 2004 rally — during Boston's 18-0 run in the third quarter on Tuesday night.

"Now we've just got to go win another one," Smart said after logging 11 points and 6 assists. "That's all that matters. We take it one game at a time. We understand the odds are stacked against us, but we're a team that believes in us no matter what, and we just have to keep going. All that matters is the next game."

There is still a mountain left to climb for the Celtics, but a weight was lifted from a demoralized team, and in its place is belief. Boston still believes it is the superior team — Malcolm Brogdon said as much between Games 3 and 4 — and they have another chance to prove it in Game 5 at home, where they are just 10-11 in the last two postseasons. Force a Game 6 back in Miami, and suddenly that burden shifts to the Heat.

"We want to come back to Miami," said Brown. "If that happens, I feel like we'll feel good about ourselves."

No NBA team has come back from 3-0 to win a playoff series in 150 tries, but 13 times a team has done so down 3-1, and the Celtics just overcame a 3-2 deficit in their second-round series against the Philadelphia 76ers. If ever there were a team to accomplish the feat, you might consider taking one that led the entire NBA in net rating against an opponent that finished the regular season with a negative point differential.

There are reasons to believe in Boston beyond Tuesday's outcome. The Celtics blew 12-point fourth-quarter leads in Games 1 and 2, but they rediscovered their resilience with no other choice but to win, erasing Miami leads in each of the first three quarters and answering every threat to theirs in the fourth.

Miami entered Game 4 shooting 47.8% as a team from 3-point range — this after being the fourth-worst shooting team in the regular season (34.4 3P%). Caleb Martin, Gabe Vincent and Duncan Robinson, in particular, combined to average nine 3-pointers on 51.9% shooting from deep through three games. They fell back to Earth, finishing 3-of-13 in the 17-point loss, closer to their regular-season averages (33.9%).

Boston's defense had a lot to do with that. As unlikely as it seemed that the Celtics could repair their disconnect on that end in two days, especially since it has been broken throughout these playoffs, they managed to come together for one night, and that translated to the dynamic offense they are accustomed to playing. They entered Game 4 shooting 29.2% from 3 as a team and made 18 of their 45 attempts (40%) on Tuesday, closer to their regular-season average (37.7%). Sixteen of those 18 triples were assisted.

"They are not going to shoot that poorly that many times in a row, particularly if they are getting some open ones," said Heat coach Erik Spoelstra. "They got a lot of clean ones tonight, so I'll have to see what kind of efforts and/or breakdowns we had with that. And then yeah, I think it's probably pretty easy to keep our 3-point shooting down. We just weren't doing things with a lot of oomph to it offensively."

"Any time you're in a do-or-die situation, it forces you to build an awareness and perspective," said Celtics coach Joe Mazzulla, whose job felt in jeopardy if his players quit again in Game 4. "It's always been there, and I think the perspective of understanding just a week ago we had it. It's just fragile during these times, so we just had to remind each other of that, and I thought the guys were pretty well connected."

Whether the Celtics can keep it together is another matter. Just don't let them win Game 5.