Greg Hardy's Rapping FAIL -- Rap Show Debacle After Domestic Violence Conviction

NFL superstar Greg Hardy -- aka "The Kraken" -- is having a bad month ... 'cause days after he was found guilty of assaulting his ex-GF, his rap show CRASHED AND BURNED on stage ... and TMZ Sports has the footage.

The Carolina Panthers defensive end (and aspiring rapper) was scheduled to host a party at Club Label on Sunday July 20th -- and graced the crowd with a special live rap performance.

Sources at the club tell us the show was a mess ... with people turning all the way down when Kraken hit the stage. Some even left the dance floor.

But the worst part (for Hardy) was during his 2nd song, the mic mysteriously died -- and a confused and disappointed Kraken eventually walked off the stage.

Sources at the show tell us crowd members suspected the DJ cut the mic to spare the crowd and save the party -- though the DJ tells TMZ Sports it's not the case ... blaming a technical mishap.

Hardy kept his cool -- which is good for him considering on Tuesday a judge had sentenced the NFL star to 18 months probation for beating and threatening to kill his ex-girlfriend Nicole Holder during an altercation back in May.