NEW YORK -- A chance to gain ground in the playoff race was there, until Jarrett Jack took it away.
Now the New York Knicks have 3,000 miles to think about how this game - and maybe any realistic postseason hopes they had - was lost.
Jack scored a season-high 31 points Sunday night in the Cleveland Cavaliers' 106-100 victory over the Knicks, who had their eight-game winning streak snapped.
The Knicks wasted a chance to pull within two games of a playoff spot before leaving for a five-game Western Conference trip that starts Tuesday against the Lakers.
''This was a huge opportunity lost, one we can't afford,'' Knicks guard J.R. Smith said. ''But we can't get it back. We've just got to go on the road, win some games and try to come back home and win.''
Hours after being handed a chance to get closer to the final spot in the Eastern Conference when Atlanta blew a fourth-quarter lead in Toronto, the Knicks responded with an inept final period of their own after they led by 17 points in the first half.
They couldn't stop Jack and couldn't get a basket fromCarmelo Anthony, who missed all five shots in the final period and finished with 32 points. New York remained three back with 12 to play.
''It's tough. We should've won this game. We gave it away. They earned it, they beat us. We didn't play well coming down the stretch or in the second half and they did,'' Anthony said. ''But it's behind us now, there's nothing we can do about that.''
Jack scored 23 in the second half after coach Mike Brown challenged his team at halftime.
''It was just about making a stand and each individual person making a stand and then collectively as a team us all bringing that same mindset to the table,'' Jack said. ''That's pretty much what it was about. I just thought guys responded.''
Jack finished with 10 assists for the Cavaliers, who snapped a four-game losing streak.
Dion Waiters scored 22 points and Luol Deng had 13 in his return from a three-game absence with a sprained left ankle for the Cavs, who didn't miss All-Star Kyrie Irving because Jack torched the Knicks for 13 points in the fourth quarter on 6-of-7 shooting.
''I just challenged them. That's all. I didn't say that much,'' Brown said. ''The guys in the locker room, they decided to go play and they went out and got it done.''
New York was missing ailing Iman Shumpert, their best perimeter defender who surely would've gotten a chance to defend Jack since nobody else could.
The Knicks, who suddenly were back in the playoff race after looking out of it after a seven-game skid dropped them to 21-40 after a loss in Detroit on March 3, will have to bounce back on the road.
The Hawks had already lost at Toronto by the time the Knicks showed up for work Sunday. Coach Mike Woodson said he was glad but didn't appear overjoyed, realizing the Knicks still have plenty to do to get to the 35 to 40 wins he think will be necessary to earn a playoff spot.
''It's good that they lose, but again, it's about what we do at this point,'' Woodson said before the game.
Even getting to 35 wins will be difficult considering they still have games against Miami and Chicago, plus two apiece against Brooklyn and Toronto after their trip.
New York made 15 of 21 shots (71 percent) in the first quarter, getting 14 points from Anthony and taking a 34-27 lead when Smith made a 28-footer with 0.2 seconds left. The Knicks pushed the lead to 17 in the second when Pablo Prigioni made a 3-pointer, then stole the ball and threw an alley-oop pass that Smith slammed down to finish off a fast break and make it 51-34.
But down 61-46 at halftime, Cleveland scored the first nine of the second half to get within six, and the Knicks never really got the momentum back.
The Cavs used an 11-4 spurt to tie it at 90 on Jack's jumper with 7:29 remaining, then Deng's 3-pointer gave them a 93-92 edge with 5:46 to play.
Anthony's free throws gave the Knicks their last lead, but Jack knocked down a jumper, Waiters made a 3-pointer and Anderson Varejao had an easy dunk after a pick-and-roll to make it 100-94 with 2:37 remaining.
New York cut it to two, but Jack answered with another jumper, finishing two points shy of his career high.
Smith finished with 18 points.
NOTES: New York had won the previous five meetings at home. ... On Noche Latina, Spanish for Latin night, former St. John's star Felipe Lopez announced the starting lineups in Spanish.