LeBron James scored 35 points and Mo Williams added 20 as the Cleveland Cavaliers stormed back in the second half to beat the Boston Celtics 101-93 Saturday night in Game 1 of their Eastern Conference semifinal series. James, playing with a sprained and bruised right elbow, delivered yet another memorable performance as the Cavs withstood the Celtics, who led by 11 in the third. James, who also had seven rebounds and seven assists, drained a 3-pointer with 22 seconds left to put Boston away, hours before he was to receive the NBA's Most Valuable Player award for the second straight season. Rajon Rondo had 27 points and 12 assists and Kevin Garnett finished with 18 points and 10 rebounds for the Celtics. Game 2 is Monday night. Dismissed as being washed up, the 17-time NBA champion Celtics controlled the tempo from the start and were on the verge of swiping home-court advantage away from Cleveland. But James, who seemed to be bothered by the elbow early on, picked it up down the stretch. After Rondo split a pair of free throws with 4:30 left, James drove the lane and missed a short shot but grabbed his own rebound and banked it in to put the Cavs ahead 94-91. Garnett's bucket got the Celtics within one, but James countered with a floater in the lane. After Paul Pierce missed a wide-open 3-pointer, Shaquille O'Neal, who looked slow and every one of his 38 years during stretches, scored on a tip to make it 98-93 with 1:02 remaining. Following a Boston turnover, James came up with the decisive blow. Pulling up on the left side, he buried a 3-pointer that finally allowed 20,000 Cleveland fans to celebrate. James, called “the closer” by his teammates, scored 12 points in the fourth. “He's a guy that is going to deliver,” Cavs coach Mike Brown said. “As the game went along he got more aggressive and the shots started to fall.” James tried just two outside shots in the first half, and came out of the locker room at halftime shaking his right arm, which he said has been bothering him periodically for a month. But the elbow appeared as healthy as ever when James needed it to respond. “Throughout the game it loosened up,” said James, who will receive his second Most Valuable Player award on Sunday in his hometown of Akron. He won the NBA MVP in a lopsided result last season. “I have a no-excuse policy. This team has a no-excuse policy. ... We're about coming out and competing against the Celtics.” James closed the third with a twisting, falling-down layup at the horn, capping a 21-9 spurt that put the Cavaliers up 79-78, their first lead since 7-6. Cleveland trailed 69-58 when Williams grabbed a loose ball and raced down the floor before slamming it over Pierce, who was probably expecting the guard to try a layup. “That surprised me,” said Brown, who struggled to keep a straight face regarding Williams' dunk. “I didn't know what happened. That was a heck of a play.” This is the second time in three years that the Cavs and Celtics are meeting in the conference semifinals, and there is no love lost between them. In 2008, the Celtics won a rugged series in seven games on their way to the championship. If Game 1 was any indication, this series could be equally entertaining. “This not going to be easy for either team, you can see that,” Celtics coach Doc Rivers said. “It's going to be a tough series.”