CLEVELAND (AP) — LeBron James scored 20 of his 28 points in the second half, and Cleveland had seven other players in double figures as the Cavaliers shook off a slow start for a 120-103 win over the Boston Celtics on Saturday night. Kyrie Irving added 21 points and Iman Shumpert busted out of a shooting slump to add 12 points and a career-high 16 rebounds for Cleveland, which moved 2 1/2 games ahead of Toronto for the best record in the Eastern Conference. The Cavs were clinging to a seven-point lead in the fourth when they opened some distance over the up-and-coming Celtics with a 7-0 run triggered by a 3-pointer by J.R.