MIAMI -- LeBron James scored 38 points, Mario Chalmers added 15 and the Miami Heat survived a 3-point barrage from New York's J.R. Smith on the way to dealing the Knicks' playoff hopes a big blow with a 102-91 victory on Sunday.
Chris Bosh added 14 points and Ray Allen had 12 for the Heat, who remained atop the Eastern Conference standings.
Smith made a Knicks-record 10 3-pointers, on an NBA-record 22 attempts, and finished with 32 points. Raymond Felton scored 14 for New York and Carmelo Anthony managed only 13, on 4 for 17 shooting.
Anthony had two points after halftime, while James had 22.
The Heat (53-23) ensured they would finish the day still ahead of Indiana atop the East standings. New York (33-45) has only four games left and will be either two or three losses behind Atlanta when Sunday ends, depending on the outcome of the later game between the Hawks and Pacers.
Miami's lead was 15 with just under 9 minutes to go after a 3-pointer by Allen, before the Knicks came up with one last rally and made it more than a little interesting. Iman Shumpert missed a wide-open 3 with 3:30 left that would have gotten New York within four. Instead, James had a layup at the other end and after Smith made his ninth 3 of the game, Chalmers answered with one of his own, making Miami's lead 97-88.
So Smith made another, giving the Knicks life.
And Miami again answered, this time Bosh doing the long-range honors and restoring the nine-point edge with 1:32 remaining. Smith missed two more 3s from there - his 20th and 21st attempts of the day - and that just about sealed things for the Knicks.
Miami was again without Dwyane Wade (hamstring) and Greg Oden (back), plus was missing Chris Andersen (back, knee) and Justin Hamilton (illness).
Amare Stoudemire scored 12 and Tyson Chandler finished with 10 points and 11 rebounds for New York.
Fighting for their playoff hopes and fueled by a ridiculously fast start - 14 points in the game's first 2:23, the best early pace by the Knicks in any game over the last decade, according to STATS LLC - New York had full control early.
The Heat were turning it over on just about every possession, and by the time the game was 3 minutes old, the Knicks were up 16-3.
That was also the score when Felton was whistled for his second foul.
Everything seemed to change in that instant.
The Knicks missed six straight shots and the Heat scored nine straight points. James - who missed most of the pregame warmup period and remained in the locker room for undisclosed reasons - settled down from a turnover-addled beginning and things started going Miami's way.
James had four turnovers by the time Miami scored six points. But he put on his customary show before the quarter was over, simply outmuscling Tim Hardaway Jr. for what became a three-point play. Hardaway tried to wrap James up on a break, but the four-time MVP just kept going, scored and then flexed a biceps muscle to the roaring crowd.
And after that sizzling 14-point beginning, New York needed more than 13 minutes to score its next 14 points. A 31-10 run helped the Heat take as much as an eight-point lead in the second quarter, before the Knicks closed strongly and went into the intermission up 50-48.
But Miami found some breathing room by scoring the final seven points of the third.
James laid it in while getting fouled with 4.1 seconds left - and as "M-V-P" chants rained down he gave Miami its biggest lead to that point, making the free throw that put the Heat up 73-64 entering the fourth.
Miami then scored the first four points of the final quarter, and never again ceded control.
NOTES: Family ties were everywhere Sunday. Example 1: Tim Hardaway Sr. - now a Heat executive whose number from the playing days is retired in Miami - went into the Knicks' locker room about two hours before the game to visit his son, who then came outside to give his sister a quick pregame hug. Example 2: Jeff Van Gundy worked the game for ABC, sitting three chairs away from former Heat coach Stan Van Gundy, working for ESPN Radio. ... Bosh had no rebounds in the first half, then grabbed seven in the third quarter alone. ... A fan clad in Knicks garb caught a T-shirt thrown into the stands by a Heat dancer during a stoppage in the fourth quarter. He immediately threw it back onto the court. ... Hardaway Jr. is 2 for 22 in his two games in Miami this season.