Derrick White had 24 points, including six from three-point range, and Boston dominated Miami 110-97 in Game 5 to extend the Eastern Conference finals.

Marcus Smart had 23 points and five steals, Jayson Tatum and Jaylen Brown finished with 21 points apiece on Thursday night and the Celtics claimed their second straight win and trimmed the Heat's series lead to 3-2.

It keeps alive Boston's hopes of becoming the first team in NBA history to overcome a 3-0 deficit to win a series. Teams previously in that position are 0-150 all-time.

Game 6 is Saturday in Miami.

"It just says that our backs are against the wall and we're sticking together and we're competing at a high level to give ourselves a chance," Celtics coach Joe Mazzulla said.

Duncan Robinson led the Heat with 18 points. Bam Adebayo added 16 points and eight rebounds, while Jimmy Butler had playoff season-low 14 points, plus five rebounds and five assists.

Boston entered the day just 4-5 at TD Garden this postseason. But with a raucous home crowd behind them, the Celtics thrived on their energy and never trailed.

They dived for loose balls, outfought the Heat for rebounds and found each other for layups and dunks in transition as they led by up to 20 points in the first half.

Miami cut into it, but Boston kept knocking down threes and grew their advantage as high as 96-72 in the fourth quarter.

"I don't want to say we're surprised by it, but they raised their level," Robinson said.

"We've got to raise ours now as well."

The Heat started Kyle Lowry at point guard after Gabe Vincent was ruled out with a sprained left ankle earlier in the day.

Smart stripped Adebayo on Miami's opening possession, igniting a fast break and layup on the other end by Tatum.

Then, with the game tied at four, Tatum got free in the lane for a monstrous two-handed dunk. He hung on the rim afterward and continued his celebration when he landed, leading to a technical foul.

It didn't stop the Celtics' momentum, as their first-quarter lead grew as high as 23-7. Boston ended the period with a 35-20 lead, punctuated by a White triple at the buzzer.

Tatum, who also finished with 11 assists for a double-double, had 12 points in the opening 12 minutes, with the Celtics outscoring the Heat 21-6 from beyond the arc, draining 7 of their 12 attempts.

"We're always going to stay positive, knowing that we can and we will win the series," Heat star Butler said.

"We just have to close it out at home."