"Just know that I'm always going to keep coming back until I don't play this game no more," Wade said. "I know my abilities, I know what I'm capable of and it was good."
He spun into the lane and found Bosh for a dunk that seemed to have the Heat safe at 98-91 inside the final minute, but a 3-pointer by Durant cut it to 98-96 with 37 seconds left. After James missed a 3-pointer, the Thunder got the ball into Durant, who appeared to be knocked off balance by James as he missed the baseline shot attempt.
Durant said only that he missed the shot, saying he would have to watch the tape to see if he was fouled.
James then sank the insurance free throws - finishing a 12-for-12 night at the line - as fans booed loudly over the no-call.
Bosh started after coming off the bench in every game since returning late last round from his nine-game absence with a strained lower abdominal muscle. The Big Three joined Battier and Mario Chalmers in the lineup, the first time Miami had gone with that first five all season.
It sent the Heat on their way to a terrific start, and Battier matched his surprising 17-point performance in Game 1 by going 5 of 7 from 3-point range, providing all the help the superstar trio needed.
James had his fifth straight 30-point game, breaking Wade's franchise playoff record, and added eight rebounds. He defended Durant early in Game 1 and helped put the league's scoring champion in early foul trouble, just one of the problems the Thunder had early.
Another loud, blue and white crowd tried to inspire them to rally, but the team could just simply never get close enough to until the final minutes.
NBA finals: Heat def. Thunder 4-1
Winderman: LeBron James has been a prodigy, superstar and villain. And now he's champion. The journey has left the league and Finals MVP humbled and happy for those closest to him.
Durant nailed a 3-pointer and drove into the lane to throw down a dunk over Battier that cut it to 82-74 with 8:22 remaining. His 3-pointer from the wing trimmed it to 90-86, and the Thunder got it all the way to 94-91 when Westbrook dunked Durant's miss with 1:48 to go.
James answered by banking in a jumper for his first basket of the final period, as the Big Three combined for all but one of Miami's seven field goals in the fourth quarter.
The Thunder missed 11 of their first 12 shots, and when James capped a run of 13 straight Miami points with a basket, it was 18-2 with 4:51 remaining in the period.
Coach Scott Brooks had talked to his team about its poor starts - this was three straight games with a double-digit deficit - and told the Thunder during a first-quarter timeout that the Heat were playing harder than they were. The Heat kept it up, pushing it to 25-8 on Wade's jumper with 2:39 left.
"We kept missing good shots," forward Serge Ibaka said. "We can do better."
PBT: The Spurs saw the NBA title slip through their fingers Tuesday night. Do they have it in them to rebound from their meltdown in time for Game 7?
Video: NBA from NBC Sports
Bosh: 'We'll see who hits first'
Heat forward Chris Bosh talks about what could be a very physical Game 6 stating, "Hit them in the mouth, throat and their eyes." Miami coach Erik Spoelstra says the opposing Spurs "attack you ... but we do the same thing."
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