The Miami Heat advanced to the NBA Finals on Monday by routing Boston 103-84 and denying the Celtics a historic comeback from down 3-0 in the series.

Jimmy Butler had 28 points, seven rebounds and six assists while Caleb Martin added 26 points and 10 rebounds to spark Miami, which will visit Denver on Thursday to begin the best-of-seven championship final.

Taking full advantage of an injury to Boston star Jayson Tatum in the opening seconds and a cold-shooting start by the host Celtics, the Heat avoided becoming the first team in NBA history to lose a playoff series after taking a 3-0 lead.

Miami recovered from a gut-punch of a game-six defeat, falling on a last-second tip-in, to win the Eastern Conference final 4-3, silencing a loud Boston crowd after the opening minutes.

"We stayed together as a group and as a team," Butler said. "We talked about going to get a tough one on the road and we did just that.

"But we're not satisfied. We're happy. We're ecstatic. But we've got one more to get."

The Heat, seeking a fourth NBA title and first since 2013, last reached the NBA Finals in 2020, losing to the Lakers.

The Nuggets, into the NBA Finals for the first time, swept the Los Angeles Lakers in the Western Conference final and have not played since May 22.

Miami stretched the lead as high as 17 points in the second quarter — a margin the Heat hadn't squandered to lose a game all season — but Boston pulled within 52-41 at half-time.

With Tatum hurting, Derrick White scored eight straight points to lift the Celtics within 59-51.

But Caleb Martin sank a baseline jumper just before the third-quarter buzzer, giving him nine in the period, to put Miami ahead 76-66 entering the fourth.

Martin sank a three-pointer to ignite a 7-0 Miami run to open the fourth quarter for an 83-66 edge, matching the Heat's largest lead to that point.

The Celtics went nearly four minutes without scoring and never again threatened, finishing a woeful 9-of-42 from three-point range.

"We shot 21 percent from three," Celtics coach Joe Mazzulla said. "The defense was still there.

"They gave it everything they had. That's the most important thing to take from this. We failed, but it's not because the guys didn't have a sense of togetherness and character."

Tatum, who finished with 14 points on 5-of-13 shooting, turned his left ankle landing awkwardly after a baseline jumper in the game's opening seconds.

He stayed in the contest but grimaced often and the prolific scorer took only one shot in the first 17 minutes.

"He just tried to play through it as best he could," Mazzulla said.

An 18-6 Heat run to close the first quarter gave Miami a 22-15 lead with the Celtics matching their season low for first-quarter points.

Boston went 0-for-10 from three-point range in the first quarter, missing the first 12 from beyond the arc overall, and made only 6-of-23 from the floor in the opening period.