Polyana Viana, 27, a Brazilian MMA fighter, was alone when this unidentified man tried to mug her with a fake gun. Image Credit: Instagram

A thief in Rio de Janiero picked the wrong target recently.

The man had discovered a painful reality after he approached UFC athlete Polyana Viana outside her home in the Brazilian city while she waited for Uber at around 8pm local time on Saturday.

Viana is a mixed martial arts (MMA) fighter who lives in the Jacarepagua neighbourhood, in the West Zone of Rio.

"When he saw I saw him, he sat next to me. He asked me the time, I said it, and I saw he wasn't going to leave," Viana, 27, told MMAJunkie.

"And then he said, 'Give me the phone. Don't try to react, because I'm armed.' Then he put his hand over [a gun], but I realised it was too soft."

Thinking the gun was fake, Viana decided to take matters into her own hands.

The result: The man left not only empty-handed, but with horribly punched-up face.

Viana further recounted: "He was really close to me. So I thought, ‘If it’s a gun, he won’t have time to draw it.’ So I stood up. I threw two punches and a kick. He fell. Then I caught him in a rear-naked choke. Then I sat him down in the same place we were before."

Viana reportedly (10-2 MMA, 1-1 UFC) subdued the man until police came to take him away. Some of the pictures were posted on instagram

The unidentified man who allegedly tried to rob UFC fighter Polyana Viana. Image Credit: Photo provided by Polyana Viana

Though she was alone, passers-by helped to call the police once she had subdued the man by keeping his arm immobilized in a kimura-like position — until police arrived.

According to Viana, they took the man to an emergency care facility to address his wounds and then to the station, where she filed a police report.

It later emerged that the "firearm" was simply a cardboard cutout.

The 'gun' used by the man who allegedly tried to rob UFC fighter Polyana Viana. Image Credit: Photo: Polyana Viana

Viana said she also learned at the station that the man had been arrested before and had only recently been released.

The Rio police department told CNN that a similar incident had occurred in the same area of the city, and an arrest was made.

Police did not state if the man was the same mugger in the previous incident.

"A criminal was found immobilized by civilians after trying to rob a person on site," a statement read. "A fake gun was seized with him."

MMAJunkie posted a photo of the alleged cardboard gun, they reported receiving from Viana.

After the incident, Viana said she was “fine”. From the image which Viana took and posted on social media, it appeared the man was most affected by the ordeal.

Pictures reportedly taken by Viana, appeared on UFC president Dana White's Instagram account showing the man's badly disfigured face.

It was the first time she been mugged in Rio, her second home. But the Saturday incident wasn’t the first time Viana experienced a mugging attempt.

Viana said it had happened in her previous home of Belem, when she was approached by two men in a motorcycle — one stayed, while the other charged at her.

“He broke my umbrella and tried to take my phone,” Viana said of the Belem incident. “I said I wasn’t going to give it to him. He tried to take it from my hand, I punched him in the face, and he was scared. This time I was scared. I don’t know if it was because there were two of them.”

“So I was scared,” she told the website, adding: “But I think he was more scared than I was, so he jumped on the motorcycle and left.”

After leaving the police station on Saturday night, Viana says she simply went home and made dinner. Viana later said her hands hurt a little but that it’s nothing serious, and she’s otherwise “unharmed”.