LeBron James was King James Thursday night.For all he has done in his illustrious career, LeBron James Thursday night in Boston eclipsed himself. Already widely regarded as the game’s best and most dynamic player, James was better and more dynamic than ever, saving the Miami Heat season and crushing the Celtics’ all at once.It was a genius performance by James, magnified by the stakes: a loss in Game 6 of the Eastern Conference finals and the Heat’s season – expected to be so much more – would be over.James would have none of it. He notched 45 breath-taking points, 14 rebounds and five assists, and Miami forced a deciding Game 7 with a dominating 98-79 victory. Now, the advantage goes back to the Heat, who host the game that will determine who will face the Oklahoma City Thunder in the NBA Finals.This was all made possible by James, the league’s MVP who has been branded by some as a failure in clutch situations. Well, there was not a more important game than Thursday night, facing elimination on the road and a heap of inevitable criticism with failure.In fact, there was talk that coach Eric Spoelstra could be fired with a defeat and that the Big Three of James, Wade and Chris Bosh could be broken up in another disappointing off-season. Pressure? It was immense.But there was no need for a last-second shot. Miami blew out the Celtics with suffocating defense and James’ assault. He was 19-for-26 from the floor, scoring 30 in the first half on 12-for-13 shooting. He scored on a dazzling array of post-ups, fadeaway jump shots and daring forays to the basket. It did not matter that Wade was invisible until late in the game; James was in command.“I just wanted to attack and do whatever it took to lead my team,” James said. “It was a must-win game for us. I’m happy we were able to put together a complete game this series. I just tried to make plays for our team. . . to give ourselves a chance to win. In an environment like this you want to have a good game. This was a gut check for us. It’s good to see we were able to bounce back after that Game 5 loss.”No one bounced higher than James.“He was absolutely fearless, and it was contagious,” Spoelstra said. “The way he approached the last 48 hours. . . nobody likes having dirt thrown on your face before you’re even dead. . . But he was fearless and everybody followed him.”There was a focus and determination on James’ face and in his game. Hardly did he whine to officials about a call. There was not a scowl to his look, but rather a purpose.Meanwhile, Boston looked sick. Paul Pierce was 4-for-18 shooting. Kevin Garnett was 6-for-14. Rajon Rondo had 21 points and 10 assists, but turned the ball over seven times. As a team, the Celtics shot just 42 percent. Overall, they just looked anemic. And they had no answer for James, falling behind by 13 at halftime and never coming closer than eight points the rest of the way.“He brought it to us and we didn’t bring it back to him,” Boston coach Doc Rivers said.