MIAMI >> Their season, their legacy, their reign atop the NBA was all at stake, and the Miami Heat responded in a manner befitting defending champions — with a blowout.

LeBron James scored 32 points and grabbed eight rebounds, ailing Dwyane Wade matched his postseason high with 21 points, and the Heat ran away from the Indiana Pacers 99-76 in Game 7 of the Eastern Conference series on Monday night.

In the NBA Finals for the third straight year, the Heat will play the San Antonio Spurs, beginning with Thursday’s Game 1 in Miami.  

“They’re just an amazing group of guys,” Heat managing general partner Micky Arison said after handing the East trophy to Chris Andersen. “They’ve given us an incredible season so far, but it’s a long way from over.”

It could have ended on Monday, of course. The Heat had alternated wins and losses with the Pacers in the first six games of the series, and were coming off their worst offensive outing of the year in Game 6.

They responded with a rout, despite shooting just under 40 percent, well below their norm.

“By any means necessary … we took care of business,” James said.

Miami led by as many as 28 points, a shocking amount for a series that had an aggregate score of Heat 569, Pacers 564 entering Monday night. The Heat actually trailed by six in the early going, were still down 21-19 after the first quarter and it was starting to look like it was starting to look like one of those down-to-the-wire nights.

Not even close.

“You never want to take anything for granted,” Wade said. “Being here three straight years in a row, going back to the finals, is an amazing feat. I’m just glad we were able to do it. Everything that happened in the first six games didn’t mean anything to us. It was about tonight. It was about Game 7. It was about finding a way to win here at home.”

James exited with 5:08 left, shaking retired soccer star David Beckham’s hand as he made his way to the Heat bench for a relatively subdued celebration. Not long afterward, security personnel started what’s become a familiar task in Miami — surrounding the court and stretching out a yellow rope, preparing to hold people at bay for the looming on-court trophy presentation.

More than a few people didn’t stick around to see the East title formally presented. After all, it’s an all-or-nothing season for the Heat — and this trophy isn’t the one that will satisfy them.

Ray Allen added 10 points for Miami, which earned its 78th victory of the season, matching the 11th-best, single-season total in NBA history.

“It’s just a privilege to be with this great team, great teammates, and we have another opportunity to go back to where we are,” Heat forward Chris Bosh said. “You never really want to get it out of the way too much. Game 7’s don’t happen too often. We enjoyed it and now we have to move on.”

Roy Hibbert scored 18 points for the Pacers, who got 14 from David West, 13 from George Hill and 10 from Lance Stephenson. All-Star Paul George was held to seven points on 2-for-9 shooting and fouled out early in the fourth quarter.

George was the last Indiana player on the floor as Miami prepped for its postgame celebration, shaking any hand he could find before being walked toward the visiting locker room by Pacers coach Frank Vogel, who slung an arm over his star’s shoulder.

His time will likely come — someday.

Not yet, though. Not with this Miami team built for titles. It’s the fourth trip to the finals for the Heat, who won the title in 2006 and have now been there all three years of the “Big Three” era, falling to Dallas in 2011 and then topping Oklahoma City in five games last year.

“The great thing is we’re a young team and we are past the building stage,” George said. “This is really our first year tasting success. The rate we are going, we see championships soon.”

They’re getting closer. A second-round loss to Miami in six games last year was followed by a seven-game, conference-finals exit this time around.

Still, they’ll be watching the title round.

“Everybody in this country knows who the Indiana Pacers are now,” Vogel said. “And we represent all the right things — class, character, hard work, old-school basketball, playing the game the right way. We represented our franchise, our city and our state extremely, extremely well, and we have a lot to be proud of.”

Miami went 2-0 against San Antonio this season, though neither of those games should be considered harbingers of what’s ahead. The Spurs rested four regulars in the first meeting, the Heat were without three injured starters in the second matchup.

“It’s crazy that it worked out this way,” Wade said.

James delivered an inspirational address of sorts to his team Monday morning, publicly revealing no details of what he said afterward other than insisting that the Heat would be ready.

He was right. After 5 minutes, it was 12-6 Indiana. After that, the rest of the half was pretty much all Miami.

Once the Pacers cooled off a bit, the Heat immediately went into pull-away mode. Over the final 19 minutes of the half, Miami’s edge was 46-25. Over the final 11 minutes, it was 33-14, as James and Allen outscored the Pacers by themselves.

Allen did less pregame shooting than usual on Monday. He was at the arena several hours before game time — as is his custom — and got in a pregame workout, but once he found a groove, he decided that was enough. And after going 13 for 46 in the first six games of the series, the NBA’s career leader in 3-pointers had to believe that he was simply overdue to get going.

His first shot on Monday was a 3-pointer that connected, giving the Heat a 26-23 lead.

The Heat never trailed again.

“We just focused on every possession, trying to get stops, play Miami Heat defense, create havoc,” James said. “I thought we did that tonight.”

By halftime, it was 52-37, with James scoring 18 points, Bosh and Wade combining for 17 and Allen adding 10 more. And what had to be most troubling to the Pacers at halftime was their 15 turnovers, a number Vogel said earlier Monday would spell trouble if his team committed that many in the entire game.

And in the third, the run the Pacers so desperately needed never arrived.

Indiana was still within 13 with 3:37 left in the period when Hibbert picked up his fourth foul. Ordinarily, that would mean someone goes to the bench, though Game 7 on the road for a trip to the finals hardly could be classified as an ordinary occasion.

So Vogel — who was second-guessed for not having Hibbert on the floor for the final moments in overtime of Game 1, when James got to the rim easily for a game-winning layup — left his center out there with four fouls.

Barely a minute later, it backfired. Hibbert picked up his fifth late in the third, and George got to five fouls by getting whistled twice in the final 46.1 seconds of the quarter.

By then, the outcome was obvious.

It was Miami’s night.

“We’ll enjoy this,” Spoelstra said, “for a short period of time.”