While waiting for an Uber outside her home in Rio de Janeiro, Viana was approached by a man who, armed with a fake gun, attempted to steal her phone.
Viana was not a thief, aiming two punches and a kick at the man before subduing him with a chokehold from behind.
The Brazilian fighter continued to control him until the culprit was treated for his injuries and taken to the police station, where Viana filed a report.
"I remember every single thing. It's like it all happened yesterday," Viana told CNN Sport via email. "The attention didn't last long, but people still ask me about it."
& # 39; I also met a lot of criticism & # 39;
Her story was covered by media around the world and shared thousands of times on social media.
Photos from the alleged incident, allegedly taken by Viana, even appeared on UFC President Dana White's Instagram account showing the man's gruesome injuries.
Handling her new found fame was something Viana liked and she tried to use it as an opportunity to empower other women who may be in a similar situation.
But she was also criticized by some who argued that the incident was not an example of what she should do in such a scenario.
"I thought it was cool to show women that we can defend ourselves, but I also faced a lot of criticism," Viana reflected.
"I ignored most things, it was my life that was in danger and I feel I did the right thing.
" To do the right or wrong, there will always be criticism. Overall, all the attention was very good to me. "
At that time, the police department failed to confirm the people involved in the incident, but told CNN Sport that an attempted robbery had taken place.
Focus on Fighting
Knowing that the media spin would likely be short-lived, Viana tried to stay entrenched and concentrate on her career.
However, the year after her ordeal, both fighters lost their two attacks.
Now, as she prepares for her next fight against American fighter Emily Whitmire on March 3, she is determined to get the title's ambitions back on track.
"I'm really confident. I want to be a UFC champion. That's my focus, and I can't wait to get it done. I work really hard, "said the 27-year-old.
" I train everything and will be ready for anything. I have complete faith that I can win. I will try to put in place my game plan and try to finish this match as soon as possible. "