Ray Allen hit the game-winning 3-point basket with 11.6 seconds left to give the Boston Celtics a dramatic 87-85 victory over the visiting New York Knicks in the opening game of their Eastern Conference quarterfinal series on Sunday.

New York's Carmelo Anthony set the stage for Allen's game winner by picking up an offensive foul with 21 seconds left. After Allen put the Celtics ahead, Anthony had one final chance to put the Knicks back in front but missed a 3-point attempt in the final seconds.

Allen finished with 24 points while Paul Pierce added 18 points and Kevin Garnett had 15 points and 13 rebounds for Boston, which hosts Game 2 of the best-of-seven series Tuesday night.

Amar’e Stoudemire had 28 points and 11 rebounds for the Knicks.

Toney Douglas hit a 3-pointer with 37.8 seconds left to give New York an 85-82 advantage. After a timeout, Garnett scored on an alley-oop dunk off an inbounds pass from Rajon Rondo to pull Boston within one. Anthony followed with the offensive foul.

Jermaine O’Neal scored 12 points on 6-of-6 shooting and Rajon Rondo had 10 points, nine rebounds and nine assists for the Celtics.

Anthony scored just 15 points on 5-of-18 shooting for the Knicks, who lost Chauncey Billups to a strained knee in a collision with 50.7 seconds left. Billups scored just 10 points.

New York led by 12 three minutes into the second half before the Celtics rallied, eventually taking a 66-64 lead on Jeff Green’s 16-footer with 9:04 remaining in the contest.

Boston trailed 51-39 at halftime after shooting just 41 percent and committing 10 turnovers.