James (right) got the better of Garnett when it mattered

LeBron James led Cleveland to an 88-77 home win over Boston to level their NBA Eastern semi-finals series at 2-2.

James had 21 points, including a slam dunk with less than two minutes left to put the Cavaliers ahead by nine.

"I just wanted to be aggressive," he said. "I hadn't had a play like that in the series... it put an exclamation point on the game."

The Cavs defence held the Celtics to their lowest shooting performance of the post-season (38.6%).

"They are one of the best defensive teams in the league," admitted Boston's Paul Pierce.

"They force you to drive or take tough outside shots. We have to do a better job with the extra pass."

The loss was the fifth consecutive road defeat in the play-offs for the Celtics who were led by Kevin Garnett with 15 points and 10 rebounds.

The best-of-seven series returns to Boston on Wednesday.