Jaylen Brown scored 25 points and Jayson Tatum added 22 as the Boston Celtics moved to the brink of the NBA Finals on Wednesday by defeating Miami 93-80.
Tatum also contributed game-highs of 12 rebounds and nine assists as the visiting Celtics took a 3-2 edge in the best-of-seven Eastern Conference finals series, which continues in Boston on Friday.
"We can't think it's over with," Tatum said. "We have to go home like we're down 3-2, with that sense of urgency. Not being satisfied. We've got things to clean up, we've got to be playing better. The job is not done yet.
"It's far from over."
The Celtics, who rallied from a 3-2 deficit to eliminate defending champion Milwaukee in the second round, are one victory from reaching the NBA Finals for the first time since 2010, when they lost to the Los Angeles Lakers.
They have not captured the NBA crown since 2008, when they beat the Lakers.
"This is a great opportunity," Brown said. "We have an opportunity to do something special."
The Celtics improved to 6-2 on the road in this year's playoffs.
A physical, defensive-minded contest was decided late in the third quarter and early in the fourth, when the Celtics went on a 24-2 run, Brown scoring 13 in the spurt and Tatum adding seven.
"We just got it going offensively," Brown said. "We stopped turning the ball over. We cleaned it up, made more shots and got settled in."
The Celtics dominated the third quarter, outscoring Miami 32-16 and closing the period with a 10-0 run for the largest lead to that point at 69-58 entering the fourth quarter.
For the game, Brown hit 10-of-19 from the floor, 5-of-9 from 3-point range.
"The game opened up in the second half," Brown said. "My team needed me to come out and respond."
Miami went 4-for-22 shooting from the floor in the third quarter.
"The consecutive missed open shots started to affect us on the other end," Heat coach Erik Spoelstra said.
"As poorly as we played offensively, we were able to compete defensively and keep them to under 100."
Boston then opened the fourth quarter with a 14-2 run to seize command at 83-60 and the Celtics held off Miami from there, an emphatic slam dunk by Brown serving notice the visitors would not be letting the Heat make the game dramatic over the final minutes.
"We played great defense in the first half. We played great defense in the second half," Brown said. "Once we started shooting the ball straight I knew we'd have a good half."
Bam Adebayo led Miami with 18 points and also added 10 rebounds. But the Heat shot only 30-of-94 from the floor and 7-of-45 from 3-point range.
"We wear teams out defensively and make it hard on them mentally and physically," Celtics coach Ime Udoka said. "If we do that we're in good shape."
- 'I played terrible' -
The Heat's starting backcourt, Max Strus and Kyle Lowry, were a combined 0-of-15 from the floor, 0-for-12 from 3-point range.
"I've got to play better," Lowry said. "Tonight I played terrible. When I get on the court I have to be better."
Al Horford added 16 points, seven rebounds, five assists and two blocks for the Celtics. The 35-year-old Dominican center seeks his first NBA crown.
"Al is old reliable," Brown said. "He gives us whatever we need."
Boston's Marcus Smart played despite a right ankle sprain and teammate Robert Williams was on the court despite a left knee injury.
Smart had five points, five rebounds and four assists plus stalwart defensive moves while Williams contributed six points, 10 rebounds and three blocked shots.
"Rob is a very big part of what we do," Horford said. "I'm impressed at his poise. He's huge for us."