BOSTON — Before Game 5 of the Eastern Conference finals, Boston Celtics coach Joe Mazzulla was asked about his team’s mentality entering a second straight elimination game.

“Just win or die,” he said.

After a dominating performance on Thursday night, the Celtics are still alive.

Boston took control early on and never looked back, shooting more than 50% from the field, forcing the Miami Heat to 16 turnovers that turned into 27 points and four players finishing with at least 20 points in a row a hilo, 110-99 in front of a raucous crowd at the sold-out TD Garden.

“Our back has been against the wall,” said Jaylen Brown, who finished with 21 points. “Obviously, we don’t envision being in this position, down 3-0, but when adversity comes, you can see what a team is really made of.

“It couldn’t be worse than being down 3-0, but we didn’t look around, we didn’t go our separate ways. We stayed together.”

The Celtics went one step closer to becoming the first team in NBA history to erase a 3-0 deficit and win a best-of-seven series. In fact, in the 151 times a series has gone 3-0, the Celtics are only the 22nd team to fall behind 3-0 with a higher regular-season winning percentage than their opponent. The previous two that did: Washington Capitols vs. Chicago Stags in 1947 and Orlando Magic vs. Celtics in 2010.

Now the Celtics will try to do something those teams couldn’t: win in Miami on Saturday night and bring this series back here for a Game 7 on Memorial Day.

“For some strange reason, even last year, we always seemed to make things a little harder for ourselves,” said Jayson Tatum, who had 21 points and double-digit assists (11) for the first time this postseason. “But what I do know is that you can see the true character of a person, of a team, when things aren’t going well, and our ability to come together, figure things out when it doesn’t necessarily look good for us. It’s unlike any team I’ve been on this year and last year, only the core group of guys could answer.

“I think that’s just a testament to our togetherness, obviously how much we love him, and we’ve got a room full of tough, determined guys who push, you look left and right of you, you think the guy next to you will do whatever it takes and he’ll go down fighting if it doesn’t work out.”

In Games 4 and 5, Boston has looked like the team that played so well the first seven-plus months of the season.

After shooting 29% from 3-point range in Games 1-3, the Celtics have shot at least 40% in the last two, including a 16-of-39 (41%) performance on Thursday night. Boston is now 38-2 this season when making at least 40% of their 3-pointers; it’s 29-31 when it doesn’t.

Turnovers were also key again. The Celtics forced 16 Heat turnovers in Game 4, converting them to 27 points. In Game 5, they forced… 16 Heat turnovers that turned into 27 points.

And his score was balanced. For the first time all season (regular season or playoffs), four Celtics players finished with at least 20 points: Derrick White (24), Marcus Smart (23), Tatum and Brown.

“I think we looked good today,” White said. “[We were] able to go out and run, make that extra pass, and when it looks like that with the shooters we have, we’re going to make them miss.

“Just keep making that extra pass and find the right guy.”

Boston has been on an emotional roller coaster for several weeks now; has won or lost back-to-back times in its last 11 games, going back to Game 2 of the Eastern Conference semifinals against the Philadelphia 76ers on May 3.

The Celtics also continued on a potentially historic path. Only three teams have forced a Game 7 after being down 3-0: the New York Knicks against the Rochester Royals in 1951, the Denver Nuggets against the Utah Jazz in 1994 and the Portland Trail Blazers against the Dallas Mavericks in 2003.

Boston is now 48 minutes away from becoming the fourth.

And while the Celtics have struggled in the Garden the past two years in the playoffs (11-11), they’ve been a totally different team on the road. Including their victory in Game 4, the Celtics are 13-7 on the road since the start of the 2022 playoffs and have won four straight road elimination games.

They’ll look to make that five with a win in Miami on Saturday.

“It’s going to take everything,” Brown said. “It’s going to be a dogfight. I figure those guys are going to play better than they did tonight, and come out aggressive.”

“We have to be ready to take their hit at home. We have to be ready to be resilient and go out there and do what we’re supposed to do.”