It was mano a mano down the stretch, with the two opposing players trying to will their respective team to a win in a matchup for the ages.
Butler was spent, James was spent, but they pushed on, making big-time play after big-time play.
With the game and a championship on the line, James dribbled into a double team and kicked the ball back out to a wide-open Danny Green for what could have been the shot of his life.
He missed it.
After that, Markieff Morris rebounded the ball but threw it out of bounds while trying to make an entry pass into the post to Anthony Davis.
The Lakers had to foul Tyler Herro, who drained two clutch free throws to put the game away.
The Heat, led by Butler's second triple-double of the Finals (35 points, 12 rebounds, 11 assists), beat L.A. 111-108 to force a Game 6.
Now Miami is "one win away from being one win away," while the Lakers, who are five-point favorites, need just one more victory to claim a 17th title.
NBA Finals Game 6 Information
Start Time: 7:30 p.m. ET
Live Stream: fuboTV
Game 6 Odds
Odds via FanDuel Sportsbook
Spread: Los Angeles Lakers (-5)
Money Line: Los Angeles Lakers (-200; bet $200 to win $100); Miami (+168; bet $100 to win $168)
Los Angeles Lakers (-5) and Over 215.5
Jimmy Buckets had to put forth an otherworldly performance to outshine King James' herculean stat line of 40 points, 13 rebounds, seven assists and three steals.
"His will to win is remarkable," Heat head coach Erik Spoelstra told ESPN's Malika Andrews. "Every young player coming into this league should study footage on Jimmy Butler. The definition of a two-way player."
It's almost unfair to say that James' effort was not enough, but that's the burden of being the best player in the world.
He made the right play, but Green's shot didn't fall.
"I mean, if you just look at the play, I was able to draw two defenders below the free-throw line and find one of our shooters at the top of the key for a wide-open 3 to win a championship," James told ESPN's Dave McMenamin. "I trusted him, we trusted him, and it just didn't go.
"You live with that. You live with that. It's one of the best shots that we could have got. Danny had a helluva look. It just didn't go down. I know he wishes he can have it again."
The Lakers will take a look at the film and recalibrate, but the one thing that could be troublesome is Davis' health.
The seven-time All-Star reaggravated a contusion in his right heel after landing on Andre Iguodala's foot in the waning moments of the first quarter.
He played through it, finishing with 28 points, 12 rebounds, three assists, three steals and three blocks, but he was obviously affected.
If L.A. wants to close out this series, they'll need Davis on the floor and aggressive.
"I'll be fine on Sunday," Davis said.
As for Miami, it's still all about staying alive.
Butler literally left it all out on the floor on Friday night, and he'll need plenty of rest until Sunday because his team will need him to do it all over again for them to have a chance to even things up.
"I left it all out on the floor along with my guys," Butler told Andrews. "And that's how we're gonna have to play from here on out. Like I always say: It's win or win for us."