ORLANDO • National Basketball Association (NBA) fans had been waiting to see how the Boston Celtics would react to their two-game collapse down the stretch and the emotional outbursts that followed in their locker room.

On Saturday, they played with the "right mentality", according to their coach Brad Stevens, as they clinched a vital 117-106 victory over the Miami Heat to cut the gap in the Eastern Conference Finals to 2-1.

Jaylen Brown scored 26 points and Jayson Tatum added 25 points and 14 rebounds for the Celtics, who avoided falling into an 0-3 hole from which no NBA team have rallied to win a best-of-seven series.

"Down 0-2 in the series, we played some games we thought we should have played better," Brown said. "We wanted to make it an emphasis to come out tonight and play 48 minutes, and we did.

"There's some great guys in that locker room. A lot of emotion, a lot of passion, but we're a family and we're here for each other.

"We exemplified that when we came out together and stayed together during some tough moments. They made a big run at the end of the second quarter, but we didn't hang our heads, we kept our will high and persevered."

After their 17-point lead slipped away in a Game 2 loss on Thursday - the second straight game they surrendered a double-digit lead - Celtics players could be heard exchanging heated words.

But they were all on the same page on Saturday, displaying a sense of purpose and maintaining their poise as the Heat narrowed a 20-point fourth-quarter deficit to five with less than a minute to play.

Marcus Smart, a perfect 10-for-10 from the foul line, produced a string of clutch free throws and the Celtics hung on for the win.

Centre Bam Adebayo led the Heat, who lost for just the second time in their 12th play-off game, with 27 points, while rookie Tyler Herro scored 22 points and star forward Jimmy Butler scored 17.

But Boston outscored Miami 60-36 in the paint and held the Heat to 38.8 per cent shooting from the floor.

"They came out, Boston did, with great force in this game," Heat coach Erik Spoelstra said.

"You do have to credit them for that. They sustained it for the better majority of the game. We were on our heels most of the game."

The Celtics were buoyed by the return from injury of Gordon Hayward, who played 30 minutes off the bench and scored six points with five rebounds and four assists in his first game in over a month.

Unlike in Game 2, when they were outscored 37-17 in the third quarter, Boston maintained control and entered the fourth up 89-74. Adebayo trimmed the deficit to five with 55.9 seconds to go, but Smart hit eight free throws as the Celtics held on.

Stevens acknowledged that his team were challenged emotionally by their two tough defeats and Game 3 "was more about what are we going to show ourselves to be".

"Our whole team was aggressive," he added. "Our whole team played with the right mentality. Marcus did a great job on a guy (Goran Dragic) who is playing better than I've ever seen him."

The Celtics will try to level the series in Game 4 on Wednesday.

AGENCE FRANCE-PRESSE, REUTERS