The quest to regain their respect began with a Monday night team gathering where Jaylen Brown said the players got a chance to discuss their feelings, “galvanize,” and rejuvenate after just an embarrassing Game 3 loss.
“We want to come back to Miami,” Brown said, for a possible Game 6. “If that happens, I feel like we’ll feel good about ourselves. Just coming together and talking it out (Monday). A lot of times when you get to this point, down 3-0, locker rooms and teams start to go in other directions. We wanted to be sure we were together.
“We looked each other in the eye and today we put our best food forward. I’m proud of our group for doing that.”
Returning to their 57-win selves was stunning considering how poorly the Celtics played in that Game 3. And it was also an indication of their desire not to finish the season on their backs. The past 48 hours have been humiliating. The Heat rubbed Game 3 in their faces, snickered at their battered opponents, and felt fully confident they were going to close this series out Tuesday at Kaseya Center.
And they got all the breaks in the early going — favorable officiating, 50-50 balls, 14 points from the suddenly magnificent Caleb Martin, and a 6-point halftime lead.
The lead increased to 9 early in the second half when the Heat again capitalized on good fortune. Max Strus had his 3-point attempt blocked cleanly by Jayson Tatum and then gathered the ball and swished his second attempt. It was the kind of play the Heat have made all series. They have been the more advantageous team. The Celtics have wilted with discouragement.
Instead of caving to the adversity or chucking threes to mount a rally, the Celtics relied on their defense and the resurgent Tatum. All-NBA Tatum was desperately needed in Game 4. He hit a pair of 3-pointers during a game-changing 18-0 third-quarter run and it was obvious he had regained his swagger.
“To start the third quarter, it could have went either way,” Tatum said. “We could have separated or (it could) have brought us together.”
Tatum (33 points, 11 rebounds, 7 assists) didn’t shoot with uncertainty. He didn’t fire up shots just to beat an aggressive Miami defense. He shot the ball as if he was the best player on the floor, better than Jimmy Butler, better than Martin. His confidence brimmed. He resembled a ballet dancer as he stepped back for threes or swooped to the basket for layups.
“We didn’t play well the first three games; we didn’t deserve to win those games,” Tatum said. “But we didn’t want those to define the season. We wanted to take it one game at a time. We’ve still got a long, uphill battle to go but tonight was a good start.”
Mazzulla may be coaching for his Celtics life. He put together the team’s best game plan of the series and they didn’t abandon those principles when the Heat made their push. He has received severe criticism over the past few days, and rightfully so, but he coached his best game as a Celtic on Tuesday.
“I think anytime you’re in a do-or-die situation it forces you to build an awareness and perspective,” he said. “It’s always been there, and I think just the perspective of understanding just a week ago we had it, and so 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.”

Brown acknowledged that he heard the rumors that the Celtics were a fractured locker room, and just because they met to clear the air Monday doesn’t mean they’re the Brady Bunch. But they are more connected than before. The goal is to win one more game, and then one more after that. All they can ask for is one more day.
“I think that showed our character,” Brown said of the Game 4 win. “Like right now, obviously we underperformed in the last three games, and you start to hear all these stories come out about X, Y, and Z (in the locker room), who knows where it actually comes from — 99 percent of them is not true at all. We wanted to stay together, and I think that was the emphasis last night before we played today, was making sure we was on the same page.
“We didn’t want to come out and lay an egg. We wanted to come out and play together, wanted to come out and trust each other, come out and 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.”
Now it’s on to Thursday’s Game 5 at TD Garden, where the Celtics will have to fight valiantly again for the privilege of one more game.
Gary Washburn is a Globe columnist. He can be reached at gary.washburn@globe.com. Follow him on Twitter @GwashburnGlobe.