You have to be either really brave or really dumb to try and mug a professional MMA fighter, who is known as 'The Iron Lady', with a fake gun made up of cardboard.

Yes, you read that right. When Polyana Viana was standing by herself waiting for a cab in a remote corner of Rio de Janeiro, Brazil, a mugger believed he had found an easy target to rob. 

Little did he know that the apparently helpless lady was a professional strawweight UFC fighter with a 10-2 MMA winning record.

According to Viana, when the thief saw her all alone he sat next to her and asked her for the time.

“I said it (the time), and I saw he wasn't going to leave. So I already moved to put my cell phone in my waist. And then he said, 'Give me the phone. Don't react, because I'm armed.' Then he put his hand over (with a gun), but I realised it was too soft,” Viana told the 'de Janeiro police.

© Polyana Viana

Judging by how close the robber was to her, Viana knew that he wouldn't have enough time to reach for the gun even if he was indeed packing. 

She quickly stood up, threw a couple of punches and a kick to his head, and once the stunned man fell to the ground, she wrapped him in a rear-naked choke from behind.

The robber's face had multiple fractures and when the police arrived, they had to take him to a medical faculty to fix him up a bit before escorting him to the police station.

When word about the incident broke out, the Iron Lady became an instant hit with people from all over the world commending her for her valour, some even showing sympathy towards the poor thief who made the worst mistake of his life and regretted almost instantaneously.

On the left is @Polyana_VianaDF, one of our @UFC fighters and on the right is the guy who tried to rob her #badfuckingidea pic.twitter.com/oHBVpS2TQt

— Dana White (@danawhite) January 7, 2019

Competition and fitness are great reasons to train in the #martialarts but #selfdefense is an even better one. #PolyanaViana #selfdefense #mma #martialarts #hardtargethttps://t.co/VI4m6yBtG0 pic.twitter.com/VLQ0hpvYLU

— The Dojo (@The_Dojo_FC) January 7, 2019

You should never mug people! You should especially never mug women!! And definitely make sure you never ever mug a female UFC fighter!!! https://t.co/jdCfX9oxCn #PolyanaViana

— Perez (@ThePerezHilton) January 8, 2019

So this piece of trash decides he's so pathetic he's going to threaten a woman and steal her phone. Thing is... that woman was Polyana Viana... a UFC fighter. This is the result. God I love stories like these. pic.twitter.com/0QA8TzMEya

— John Campea (@johncampea) January 7, 2019

I mean, if you're going to run around trying to mug people in Brazil, you'd better have a strong rear-naked choke defense. That's just a given. https://t.co/zBlvK7QQmS

— Ben Fowlkes (@benfowlkesMMA) January 6, 2019