Born a man, Fallon Fox became a woman through surgery and then trained to fight in mixed martial arts.
Now that she has won her first two bouts -- both in the first round -- she has gone public as a transgender fighter, the first on record in a popular sport that some consider as the successor to boxing.
"The reaction has been positive," said Fox, 37, who revealed her story recently to Sports Illustrated after a journalist with another publication began to investigate her private surgery. "It's just some people, some of society doesn't get it yet. And this is what we're trying to do now is to inform people and let them know about transgender athletes."