LaVar Ball Butchers Nas Song on 'Lip Sync Battle'

Oh man ... this is painful.

LaVar Ball took the mic on "Lip Sync Battle" and decided to do his biggest, ballerest version of the Nas classic, "Hate Me Now" ... and yeah, everyone hates him now.

Including his son, Lonzo Ball.

The Balls competed against each other on the show (airs Thursday) -- Lonzo did "Band and Boujee" by Migos, accompanied by a bunch of twerking girl dancers.

When LaVar got his shot, he tried really hard -- but it became very obvious he didn't really know the words and just sorta jumped around and mouthed a bunch of incorrect lyrics.

Afterward, Lonzo told his dad ... "If I was Nas I'd be mad he put on a performance like that on my song. I'd be mad."