ATLANTA — When the Celtics lost Game 1 of this playoff series here, the night ended with guard Avery Bradley in the locker room with a hamstring strain so severe that he needed a staff member to put on his socks.

Although the Celtics have somehow withstood Bradley’s injury, there was no way they could overcome the loss of their All-Star point guard, Isaiah Thomas. And when Thomas left Boston’s 110-83 Game 5 loss with an ankle injury in the fourth quarter, surely there was concern.

Afterward, though, Thomas stood at his locker with his left ankle lightly taped. He put on his own socks and walked toward a crowd of reporters and delivered a message to his teammates: He needs help.

For so much of the night, the Hawks had made the Celtics find someone, anyone but Thomas, to hurt them. They face-guarded Thomas. They trapped his pick-and-rolls. They sent two players to him and sometimes even three. Thomas later said he had not been guarded so closely since high school.

“It should be a sign of disrespect to my teammates for them to put two on the ball every time I have it,’’ he said. “Other guys have to step up and make plays, that’s what it comes down to. If they try to do it again in Game 6, it comes down to other guys making plays.’’

Thomas said he initially tweaked his ankle in the fourth quarter of Game 4 before aggravating it in Game 5. He was expecting the joint to swell slightly overnight, or when the Celtics fly home at noon on Wednesday. But he insisted he would play in Game 6 on Thursday.

The home team has won all five games in this series, and the good news for the Celtics is that the next one will be played in Boston. The bad news is that they will have to find a way to win at Philips Arena at some point. But they will worry about that reality if it arrives.

“You’ve got to throw this out the window and block it out and get ready for Game 6,’’ guard Evan Turner said.

The Celtics were outscored, 54-26, in the first quarters of Games 1 and 2 here. They knew they could not afford a similar lapse on Tuesday, and they did not have one. In fact, coach Brad Stevens said that his team’s defense over the first 16 minutes was as good as it ever has been.

The Hawks made just six of their first 34 shots. The Celtics were not perfect on offense, either, but they scraped and clawed to a 29-19 lead despite the fact that Thomas had not scored. But Thomas being held without a point is generally not a sustainable route to success, and holding the Hawks to 17.6 percent shooting is simply not sustainable.

A layup by Paul Millsap kicked off a stretch in which the cold-shooting Hawks simply could not miss. The Celtics tried mixing in a zone defense, but it did not help. Atlanta made 11 shots in a row overall, turning the 10-point second-quarter deficit into a 47-39 halftime lead.

“I don’t think they missed for an hour,’’ Turner said. “What could you possibly do?’’

Thomas, who was retroactively assessed a flagrant foul for swiping Hawks point guard Dennis Schroder in the face in Game 3, was booed lustily each time he touched the ball on Tuesday, just as Celtics fans had greeted Schroder in Game 4. But that was the least of his concerns as he tried to navigate Atlanta’s defense.

“Obviously if they’re doubling [Thomas] it means they’re a man short,’’ guard Marcus Smart said. “It means we have the advantage. We’ve just got to attack that advantage.’’

Late in the second quarter, Thomas began to press. As he looked for an opening, he traveled. After that, he curled through the lane and lofted one of his signature floaters, but it was an airball. He did not score during the first half.

With 10:23 left in the third quarter, he finally broke free for a jump shot, and there is always a sense that one basket by him can quickly morph into something bigger. But it did not.

With 5:28 left in the third period, two free throws by Smart pulled the Celtics within 66-57, and then Atlanta began a long-range assault. Kyle Korver, Schroder, Mike Scott, and Millsap each hit 3-pointers over a stretch of just two minutes. By the time Schroder stole the ball in the backcourt and converted a layup with 2:15 left, the Hawks had unfurled a devastating 18-1 run to take an 82-58 lead. After their 6-for-34 start, they went on to make 27 of their next 38.

The Celtics trailed by 29 points when Thomas suffered the fourth-quarter ankle injury. He hurried to the locker room afterward. It was worth questioning why Thomas was still in the game, but Stevens said he had seen this team come back from so many massive deficits that he wanted to give it one last chance. Now, the Celtics might have one last chance to continue their season.

Adam Himmelsbach can be reached at adam.himmelsbach@globe.com. Follow him on Twitter @adamhimmelsbach.