Cleveland, OH (Best E Casino) - LeBron James scored 21 points and dished out 13 assists as the Cleveland Cavaliers pulled away down the stretch to beat the Boston Celtics, 88-77, evening their Eastern Conference semifinal series after four games.

Wally Szczerbiak and Daniel Gibson each tallied 14 points for the Cavaliers, who played spectacular defense in the fourth quarter, holding the Celtics to 5-of-16 shooting in the last 12 minutes.

Kevin Garnett had 15 points, but just two of those coming in the second half, for Boston. Rajon Rondo and Ray Allen also scored 15 apiece, but none coming in the fourth quarter. Paul Pierce scored 13 for Boston, which finished at 38.6 percent from the field, including 3-of-14 from three-point range.

The Celtics, who lost 108-84 at Quicken Loans Arena on Saturday, continued to struggle on the road in the postseason, losing all five of their away games thus far. Game 5 of this best-of-seven series will be in Boston on Wednesday.

James, who shot 7-of-20 from the field, also had six rebounds, three steals and a pair of blocked shots. However, it was his emphatic jam that sealed Cleveland's momentous victory.

P.J. Brown's jumper pulled the Celtics within 76-73 with 6:29 remaining, but Boston got no closer. James countered with a three-pointer before Pierce hit a bank shot.

However, Gibson drilled a three-ball with 2:38 left, and after Pierce and Allen both missed long-distance shots James had the defining moment of the contest. James drove to his right, past Pierce and James Posey before throwing down a right-handed tomahawk jam over Garnett with 1:45 left for an 84-75 difference.

It was a back-and-forth contest for the opening quarter. James' acrobatic layup, which turned into a three-point play after he was fouled by Allen, gave the Cavs a 14-13 lead. They were in front, 23-21, going into the second.

Cleveland ran out to an eight-point lead midway through the second. Anderson Varejao's layup extended the margin to 39-31 with nearly 5 1/2 minutes remaining until halftime. A little over a minute later, James was dribbling on a fast break when he was wrapped up by Pierce in a bear hug for a foul. The ensuing foul shots made it 41-33.

The Cavs then went cold from the field, with the Celtics scoring eight in a row, capped by Brown's jumper from the left baseline. During that time James picked up his third foul, but Cleveland led 45-43 at the half, thanks to Gibson's two free throws in the closing seconds.

It remained tight throughout the third quarter, but the Cavs grabbed a 68-65 edge going into the fourth with Varejao accounting for the final basket of the period.

Game Notes

Cleveland's Delonte West departed the game with left eye irritation in the first quarter, but returned. He had six points...The Cavs shot 45.5 percent from the field.