UFC's Paige VanZant -- Bringin' Sexy Back ... With Ass-Shakin' Dance Video

Here's UFC superstar Paige VanZant dancing to Justin Timberlake ... in a bra ... and shaking her ass.

VanZant was a hardcore dancer as a teen -- and says her background has played a huge role in helping her train as a UFC fighter.

In fact, the 21-year-old has a huge fight coming up on Dec. 10th against Joanne Calderwood at UFC Fight Night 80.