LeBron James scored 21 points, jamming in a powerhouse dunk over a defenseless Kevin Garnett in the final two minutes, and the Cleveland Cavaliers beat the homesick Celtics 88-77 in Game 4 on Monday night to tie the best-of-seven series at 2-2.

Still stuck in a shooting slump, James dominated down the stretch and finished with 13 assists -- four in the fourth quarter. The Cavaliers, whose defense has been overlooked, held the Celtics to just 12 points in the final period.