Ray Allen had 20 points for Boston and Kevin Garnett, who missed the final 25 games of the regular season and the playoffs with strained ligaments in his right knee, added 16. Rajon Rondo had 16 assists and eight rebounds as the Celtics improved to 3-0.
Eddie House came off the Boston bench and was shooting freely in garbage time, finishing with 22 points.
John Salmons led the Bulls (1-1) with 16 points and 10 rebounds. Jannero Pargo had 13 points, and Tyrus Thomas and Joakim Noah 10 apiece.