The story goes that JAY-Z stabbed Lance "Un" Rivera in 1999 at the Kit Kat Club in NYC because Rivera leaked Hov's Vol. 3... Life and Times of S. Carter album before its release.

It's more than just a story ... Hov got three years probation for the stabbing after all sorts of high-priced legal wrangling

Now Rivera is saying it never happened.

In a chat with DJ Vlad, he says he's certain Hov wasn't the stabber.

"No, JAY-Z wasn't the one who actually stabbed me," he said when asked about the night.   "JAY-Z and me had a conversation before I got hit in the head with a champagne bottle ... I don't know where they got JAY-Z stabbed me.  Because if anyone knows JAY-Z the know he's a nice guy.  He's an artist. He's a poet.  He's gifted.  It's never been his history."