MIAMI » With the outcome decided in the final seconds, LeBron James walked toward Mario Chalmers to begin his version of a celebration.

He playfully punched his teammate twice in the chest.

Fitting, because James and the Miami Heat have now landed two blows against the Boston Celtics.

James scored 24 of his 35 points in the second half, Dwyane Wade added 28 and the Heat used a late 14-0 run to pull away and beat the aching Celtics 102-91 in Game 2 of their Eastern Conference semifinal series yesterday.

"Feel good about it," James said. "Series is far — far, far, far — away from over. It’s really just beginning for us."

James shot 14-for-25 from the field, and logged 44 minutes with no turnovers. Chris Bosh finished with 17 points and 11 rebounds for Miami, which leads the best-of-seven series 2-0.

Game 3 in Boston isn’t until Saturday, and the Celtics may be particularly thankful for the break.

Rajon Rondo played through a balky back to score 20 points and add 12 assists for Boston, which got 16 points from Kevin Garnett and 13 from Paul Pierce — who retreated to the locker room for treatment on his strained left Achilles’ in the first half. Ray Allen was held to seven points, and left with what he said was a bruised chest cavity, courtesy of an elbow from James in the third quarter.

"Being down 2-0 doesn’t scare any of us, doesn’t make us nervous," Allen said. "It’s just an opportunity to come out shining."

Boston tied the game at 80 on two free throws by Pierce with 7:10 left. The Celtics missed their next six shots and Miami pulled away.

To win this series, Boston will need to prevail four times in a five-game span — which it did in the first round against Miami last year, then again in the second round at the expense of James and the Cavaliers in the East semis. So it can be done, but neither James (7-0) nor Wade (5-0) has ever been part of a playoff series defeat after their clubs won the first two games.

"This is a great team we are going against right now," James said. "We’re just trying to give ourselves a good chance to win, just try to keep on attacking them, playing as hard as we can defensively, just trying to wear them down throughout the game, but it’s a great team."

James scored 12 points in the third quarter, one more than he managed in the first half, to help Miami take a 72-67 cushion into the final 12 minutes. James then added the first basket of the fourth, but Boston answered with a 13-6 run over the next 4 minutes to knot the game at 80.

The outcome was undecided — momentarily.

That’s when Miami’s big run began, including a three-point play where James dunked and got fouled after Joel Anthony kept an offensive rebound alive. Chalmers started it all with a 3-pointer — his only points of the night — off a pass from Wade, and Miami was on its way.

"Great trust," Heat coach Erik Spoelstra said. "Now the mental discipline begins," Spoelstra said. "This thing is just getting started."