Kelly Herron, 36 from Seattle, was four miles into a ten mile run through a busy park last Sunday when she stopped to use a public bathroom.

As she was drying her hands she “became aware that something was wrong” and turned around to see a man, who had been hiding in one of the toilet stalls, standing behind her.

“He immediately took me down to the ground, hit both my knees and legs, and then it was a fight on the bathroom floor and I just kept screaming, 'not today m***** f*****,’” she told ABC News.

As she was beginning to lose consciousness, she decided that “this doesn’t have to be a fair fight” and began fighting back.

“All those little things that I learned in my life… how to punch and everything came back to me,” she said. “I learned [to aim for] hard bones and soft fleshy places so I just started hitting the side of his head."

Sharing a photo of her bruised and bloodied face on Instagram (below) she wrote, “I fought for my life… clawing his face, punching back, and desperately trying to escape his grip - never giving up.”

Herron said that she was able to eventually escape from the attacker and trap him in the bathroom with the help of a passerby until the police arrived.

“Thankfully I just took a self-defence class offered at my work and utilised all of it,” she wrote. “My face is stitched, my body is bruised, but my spirit is intact.”

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Sharing another photo of herself following the attack, this time to illustrate the bruising she received to her arms, she added, “I couldn't remain the silent, anonymous victim – there is a message of survival that is too important to remain untold.”

The police report of the incident names the attacker as Gary Steiner, a 40-year-old registered sex offender in Arizona, who is currently being held in prison with a bail of $750,000 (approximately £614, 250).

ABC reports that he is facing charges of both attempted rape in the second degree and second degree assault.

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Herron later shared an image of Steiner on her Instagram page along with the words “not today m****** f*****” which, she said, became her “battle cry” when he was assaulting her.

Herron said she feels empowered, rather than afraid, following the incident and is still training to take part in the Seattle Rock and Roll Marathon, which takes place later this summer.

Images: Instagram