Andre Stoudemire scored a game-high 21 79, on Wednesday.
Jeremy Lin scored 18 points -- although he made just 4-of-17 attempts from the field -- and Carmelo Anthony contributed 10 for the Knicks, who remained undefeated under interim head coach Mike Woodson at 5-0.
Jrue Holiday paced Philadelphia with 16 points while Jodie Meeks, Lou Williams and Andre Iguodala each netted 13 in the loss. Elton Brand had a 12-point, 12- rebound double-double in the defeat, the Sixers' fourth in their last five games.
Williams drained a three-pointer to tie the game at 63 apiece midway through the fourth, but Stoudemire responded with a dunk and a pullup jumper before Lin dropped in four straight points, and the Knicks lead thereafter.
The Sixers missed their first 14 shots as the Knicks rolled out to a 13-3 lead.
New York held a 19-11 advantage after one quarter, and led by as many as 12 in the second before settling on a 43-35 halftime edge.
Philadelphia took its first edge of the game at 49-48 on a 12-3 run capped off by an Iguodala trey.
But after the teams traded the lead a few times, Tyson Chandler opened a 7-0 Knicks flurry with an alley-oop dunk from Baron Davis. J.R. Smith netted a trey to finish the spurt, and Philadelphia never regained the lead.
New York won the season-series, 2-1...Davis returned to the lineup for New York after missing two games with a right hamstring strain. He finished with five points and three assists in just over 12 minutes of game time...Knicks' starter Jared Jeffries left the game at the 11:33 mark of the fourth with a sore right knee...Philadelphia shot 38.7 percent (29-of-75) from the field while New York shot 36.7 percent (29-of-79).