The 76ers came no closer than four points after falling behind by 15 with 9 minutes to play. Philadelphia had a six-game winning streak snapped.
Anthony needed 24 shots from the field to get his 25 points and he made all of his eight free throws. It was the Knicks' fourth straight victory.
Amare Stoudemire added 20 points and nine rebounds for New York and Josh Harrellson had 13. New York won despite making only 41 percent of its shots while taking advantage of a team playing its third game in as many nights.
Andre Iguodala and Evan Turner both had 16 for Philadelphia.