In the first meeting between the rivals since the Lakers won a Game Seven duel to capture the NBA title, Paul Pierce scored 32 points and the East-leading Celtics overcame a season-high tying 41 points from Kobe Bryant to triumph at the site of last summer's heartbreak.
"It is another game but it's definitely an emotional game especially since losing Game Seven here," Pierce said. "It's a big game just knowing that we can come into this building and get a win."
Boston (36-11) trailed by seven in the third quarter, but Pierce caught fire with 12 straight Celtics points to help the visitors claim a 77-72 edge with a period to play.
A late assault by Bryant brought the Lakers (33-15) within four points in the final five minutes, but Boston got late baskets by power forward Kevin Garnett and guard Ray Allen, who finished with 21, to clinch the game with a 16-4 run.
Garnett had 18 points and 13 rebounds and point guard Rajon Rondo put up 10 and 16 assists to fuel the Celtics.
Boston, which scored a season-low 71 points in a 17-point loss to the Phoenix Suns on Friday, rebounded by shooting 60 percent in their high profile rematch with the Lakers.
In a display of great chemistry, the Celtics piled up 34 assists while the Lakers had just 10 and relied mostly on the offense of Bryant who made 16 of 29 shots.
"I didn't think anyone else wanted the ball," said Los Angeles coach Phil Jackson. "At times it didn't look like we were running anything out there offensively."
Lamar Odom had 15 points off the bench for the Lakers, who have lost two straight.