The victory broke a four-game losing streak for New York, during which its four-game advantage over Brooklyn in the Atlantic Division shrank to one before Sunday's contest.
The victory, coupled with the Nets' earlier loss to Memphis, gave the Knicks some breathing room atop the division standings.
New York broke the game open with a 17-2 run to begin the second period.
Jrue Holiday led the slumping 76ers with 30 points.
Evan Turner contributed 21, eight assists and six rebounds as Philadelphia fell for the fifth straight outing.