UFC's Casey O'Neill Busts Out Raygun Breakdance to Celebrate Victory

UFC fighter Casey O'Neill is shouting out Olympian Rachael "Raygun" Gunn -- after a UFC 305 victory she busted out the Aussie's breakdance ... but it was way more mocking than tribute.

Casey defeated Luana Santos by a unanimous decision at UFC 305, which was held in Perth, Australia -- so, naturally, the Aussie fighter had to celebrate with an impersonation of her countrywoman ... AKA the most meme'd athlete of the Paris Olympics.

She fell to the mat, laid on her side and started doing Raygun's writhing move ... and even threw in her infamous kangaroo hop. Casey's version was hilarious, for sure, but only because she was NOT competing in the Olympics when she did it.

Casey gave her version of the routine a 10, and later joked, "think if they do bring [breaking] back for 2028 I might need to take an MMA hiatus and go get a gold medal."

While Raygun's become a viral sensation, all the Internet mocking is getting to her. Late last week she called it "pretty devastating," and asked the trolls to stop harassing her and her family and friends.