Pierce had 24 points and 15 rebounds while Green led the Celtics with 27 points on 10-of-14 shooting from the field as the Celtics (38-35) had their modest two-game winning streak snapped. Carmelo Anthony scored 24 points to lead the Knicks, who won their eighth straight to improve to 46-26. Big man Chris Copeland came off the Knicks bench to score 22 points, as New York won the season series, 3-1.
While Pierce and Green were highly productive, Boston’s three other starters, Avery Bradley , Chris Wilcox  and Brandon Bass  could only manage two points apiece and combined to shoot 3-for-11 from the floor.
The loss all but assured the Celtics of seeing their five-year reign atop of the Atlantic Division come to an end. Boston is 8.5 games behind the Knicks but more importantly, now 2.5 games behind the sixth-place Hawks in the Eastern Conference. The Celtics are now just 2.5 games ahead of eighth-place Milwaukee, two games in the loss column.
The Knicks raced out to a halftime lead of 65-48 thanks to a scorching performance from beyond the 3-point circle. The Knicks made 11-of-16 attempts from 3-point range as the Celtics allowed a season-high in first-half points. New York finished 14-of-27 from long range while the Celtics were just 7-of-25 from 3-point range.
Anthony had 18 of his 24 points in the first half to lead New York.
The Celtics were within 11, 55-44, when the Knicks closed out the first half on a 10-4 run. Boston closed to within 11 again midway through the third but the Knicks again closed with a big run, 11-4, to head into the fourth quarter with a comfortable 86-69 lead.
Avery Bradley continues to struggle, finishing with just two points in 24 minutes on 1-of-5 shooting with one rebound and one assist before fouling out in the final two minutes.
Pierce did not play in the fourth quarter as the Knicks built their lead up to as many as 21. Pierce was spotted with an ice pack on his right foot for the entire quarter. The Celtics said it was simply a precaution and that there is no serious injury involved.
The Celtics left immediately after the game for a game Monday night in Minnesota against the Timberwolves . Boston returns home for a Wednesday night game against Detroit, a game that kicks off a four-game homestand at TD Garden. For more, visit the Celtics team page at weei.com/celtics .