UFC's Paige VanZant: I'm Going to Fight Mark Ballas

Bad news for Mark Ballas ... you're going to get your ass kicked -- courtesy of UFC superstar Paige VanZant.

Paige joined the guys on the "TMZ Sports" TV show (airing Friday on FS1) -- when she told us her "Dancing with the Stars" partner really believes he could last 1 MINUTE with her in the octagon.

So, Paige says she's calling his bluff -- insisting Mark has agreed to put his money where his (soon-to-be bruised) mouth is and square off with her ... a la Turtle vs. Rousey in the "Entourage" movie.

Paige says Mark wants to push the fight back (presumably until after the 'Dancing' finale) because he doesn't want to risk getting hurt ... but insists, "It's happening."

Nice knowing ya Ballas ...