Spotted: Paige VanZant and Cris "Cyborg" Justino training together Thursday afternoon. The two did a little bit of sparring, and the whole affair was documented on Twitter.

Additionally, VanZant thinks Justino is the best female fighter in the world. I doubt reigning bantamweight champion Amanda Nunes will take kindly to that, especially since Justino may not be in the Octagon any time soon due to being popped for a banned substance. But you know, secret ninja training looked fun.

Secret ninja training at an undisclosed location in Southern California with @PaigeVanzantUFC — Cyborg (@criscyborg) February 2, 2017

Not often you get to train with the the best female fighter in the world! Iron sharpens iron!!!!! #blessed @criscyborg pic.twitter.com/RqrmU5zf5j — Paige VanZant (@PaigeVanzantUFC) February 2, 2017

If I were VanZant, I'd be worrying about getting punched out of the gym.