BOSTON (CBS) — The game was all but over, but the rivalry was just heating up.

With 3:44 left to go in the fourth quarter and the Heat leading the Celtics by 15 points in Game 1 of the Eastern Conference finals, LeBron James gathered a rebound and was fouled hard by Kevin Garnett while trying to go in for a layup. James, already with 31 points at that moment, knew the game was well in hand for his team, so rather than respond aggressively, he took an alternative approach.

He laughed. Right in Garnett’s face.

With Garnett standing his ground, James simply stood his, too, holding the ball for the referee while three times yelling “Yeah!” with a smile on his face.

It can hardly be considered a confrontational showdown, and it can’t even be considered taunting, really. But considering how bothered Garnett said he was by newspaper columns that he didn’t even read in the first round, you know LeBron’s laughter is an image he’ll be thinking of over the next two days.

For his part, James said afterward that it was all part of the fun of the game.

“I think we all know how KG is,” James told ESPN’s Doris Burke shortly after the 93-79 Heat victory. “He always does a lot of talking, but it’s all in the fun of the game. He’s a great competitor. I love to compete too at the highest level. That’s what it’s going to be throughout the series.”

Garnett wouldn’t take the bait in turning the incident into a war of words.

“It’s all good. They’re home, they’re comfortable. And when you’re comfortable, you do things like that,” Garnett said. “We’ve got to make sure we take them out of their comfort zone and fight a little harder.”

Point guard Rajon Rondo echoed that belief.

“I mean, [we don't want to do] nothing dirty, but you know, they [the Heat] have to hit the deck, too,” he said.

Whether or not the LeBron laughter will be the reason, it’s clear the intensity is just beginning to ramp up for this series.