Pierce dished off seven assists and Kevin Garnett chipped in with 14 points and 10 rebounds as Boston beat a team with a winning record for the first time this season.
The Celtics improved on a lackluster home record, moving to 2-5 in their last seven contests in Boston.
The Magic set a team record for fewest points scored in a game. Orlando could manage only 24.6 percent shooting from the floor and turned the ball over 25 times.
Dwight Howard led the Magic with 18 points and 14 rebounds.