The fifth-seeded Heat finished off their upset of the NBA's best regular-season team as reigning MVP Giannis Antetokounmpo watched from the bench area. Antetokounmpo missed most of Game 4 and all of Game 5 because of a sprained right ankle.
"We have deep, deep respect for that franchise and it's unfortunate that Giannis couldn't play tonight," Heat head coach Erik Spoelstra said.
Jimmy Butler and Goran Dragic each scored 17 points for the Heat, who will play either the Boston Celtics or the defending champion Toronto Raptors in the conference finals. It marks the first time that Butler has reached the NBA's final four.
"It means a lot, but that's not my goal," Butler said. "That's not my guys' goal. That's not the organization's goal. We want to win it. We want a championship and I think that's what we're focused on. These next eight are going to be much harder than the previous eight. We know that, but we're ready for them."
Heat forward Jae Crowder had 16 points and six rebounds, while Bam Adebayo notched 13 points and six boards. Tyler Herro had 14 points on 3-of-7 shooting from 3-point range and Kelly Olynyk added 12 points and six rebounds in 17 minutes off the bench.
The decision to hold Antetokounmpo out came down about 45 minutes before tip off.
"I wanted to play," Antetokounmpo said. "You know I wanted to play. I know I wanted to play. My coach knows I wanted to play, but at the end of the day, the organization put my health over Game 5. That's big."
Miami is making its seventh trip to the conference finals since 2005 -- the most of any team in the Eastern Conference. The Heat became the lowest-seeded team to reach the East finals since the eighth-seeded New York Knicks in 1999.