Cleveland, OH (Sports Network) - Mo Williams sparked the Cavaliers in the third quarter and LeBron James finished off the Boston Celtics in the fourth, scoring 10 of his 35 points in the last six minutes to lift Cleveland to a 101-93 win in the opening game of the Eastern Conference semifinals.
James, wearing a protective sleeve on his injured right elbow, added seven assists and seven rebounds for Cleveland, which scored the final seven points to seal the win. James is expected to pick up his second straight MVP trophy on Sunday.
"It's been better, but I don't use excuses," said James of the elbow. "I'll be ready for [Game 2]."
Paul Pierce logged 13 points on 5-of-17 shooting in defeat.
Game 2 of the series is scheduled for Monday in Cleveland.
Williams' third frame helped the hosts erase a double-digit deficit, and it was a tight game until Cleveland took over down the stretch.
O'Neal broke a 90-90 tie with a layup and then sent Rondo to the ground with a hard foul the next time down. Rondo recovered and hit 1-of-2 free throws, and a James basket made it a 94-91 game with under 3 1/2 minutes to go.
Garnett's make inside cut the deficit to one, but James answered at the other end with 1:48 to play.
Kendrick Perkins grabbed an offensive rebound and kicked it out to Pierce, who missed the original attempt and then hit all iron on a three from the corner.
A pick-and-roll led to James feeding O'Neal down low, and the former league MVP cleaned up his own miss for a 98-93 advantage with 1:02 remaining.
After Perkins lost the ball out of bounds, Boston opted not to send Cleveland to the foul line, and James' three from the left wing with 22.9 seconds showing sealed the outcome.
Rondo's buzzer-beating three yielded a 26-20 lead at the end of the first, and the shifty guard scored 10 points in the second to keep the Celtics in front.
Ray Allen and Perkins hit consecutive field goals just past the midway mark of the frame for a 42-33 edge, and Perkins put back a Rondo miss just before the halftime gun went off for a 54-43 score.
Boston had an 11-point lead on several occasions in the third, the last occurring near the midway point when Allen sank a three-ball to boost the margin to 69-58.
Williams suddenly got hot and went on a personal 10-4 run, highlighted by his first ever dunk as a Cavalier. Two Anderson Varejao free throws a little later cut the deficit to 73-71, and James rattled one in at the buzzer that put the Cavs on top, 79-78.
"We stuck together throughout the game," Cleveland head coach Mike Brown said. "As the course of the game went on, we really kept our composure."
James is scheduled to undergo daily treatments and a repeat MRI for his strained elbow..Boston beat Cleveland in the East semis two seasons ago en route to the NBA title...The Cavs and Celtics split four games in the regular season...Both clubs finished off their opening round opponents this year in just five games, as Cleveland dispensed of Central Division rival Chicago, while the Celtics sent the Miami Heat back to South Beach...Cleveland has won 13 of its last 14 postseason games at Quicken Loans Arena...Allen scored 14 points for Boston, which shot 44.4 percent overall...Cleveland turned 16 Boston turnovers into 23 points.