Days after successfully repelling a brutal attack while out for a run at a park in Seattle, one jogger has gotten her stride back.

Kelly Herron, 36, spoke to ABC News about how a day of marathon training turned into a runner's nightmare situation, and how she countered the attack the moment she said she realized "this doesn't have to be a fair fight."

Four miles into what was supposed to be a 10-mile run through the popular Golden Gardens park on Sunday, Herron stopped to use a public restroom.

"As I was drying my hands I became aware that something was wrong," Herron said. When she turned around, she said she saw a man standing in the bathroom. At that point, according to police, Gary Steiner -- a 40-year-old registered sex offender in Arizona -- assaulted 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*****.'" Repeatedly screaming the phrase at him throughout the entirety of the attack, Herron said it became her "battle cry."

Herron recalled that at one point in the agonizing ordeal, she was able to escape from her attacker into a bathroom stall, but was only able to keep him at bay momentarily.

"I got into that stall flipped on my back and I tried to kick the door lock shut with my foot," Herron said. But she missed the lock and jammed the door. Steiner came into the stall from the side and she said "he started beating me in the face with his hand."

Herron said she had a moment of clarity when she realized "this doesn’t have to be a fair fight" and began to scratch his face.

"All those little things that I learned in my to punch and everything came back to me," she said. "I started to feel like I was going to lose consciousness...but I got another surge of adrenaline and I reached for the door and was able to get out."

Herron said a passerby outside of the bathroom had a carabiner on hand that they used to lock Steiner in the bathroom.

Herron posted a photo of her bruises and stitches to Instagram as a badge of her brave escape.

My biggest running nightmare became reality- 4 miles into my long run Sunday afternoon, I stopped to use the restroom and was assaulted by a man hiding in a stall (that is my GPS in red lines). I fought for my life screaming("Not today, M**F**er!"), clawing his face, punching back, and desperately trying to escape his grip- never giving up. I was able to lock him in the bathroom until police arrived. Thankfully I just took a self-defense class offered at my work and utilized all of it. My face is stitched, my body is bruised, but my spirit is intact. #fightingchanceseattle #ballard #runnersafety #marathontraining #womensselfdefense #myballard #fightlikeagirl #fightback #dontbeavictim #nottodaymotherfucker #youcantbreakme #instarunners #garmin #garminvivosmarthr

A post shared by Kelly Herron (@run_kiwi_run) on

Mar 6, 2017 at 10:48am PST

Herron said she was able to maneuver with self-defense tactics that she had learned in a class just three weeks earlier.

"I learned hard bones and soft fleshy places so I just started hitting the side of his head," she said.

Jordan Giarratano, an instructor at Fighting Chance Seattle who has taught self-defense for over 20 years, said in all his years he has never seen a student use what they have learned in this sort of situation.

"This is one of the most surreal things I've ever the four years I've been running this workshop," he told ABC News. "It's very inspiring and overwhelming and humbling."

One survey in Runner's World magazine found that 43 percent of women experience harassment while running. Unlike Herron's case, most are not life-threatening, but in a deadly nine-day stretch this past summer, three women in three different states were murdered while running.

Giarratano told ABC News that people who are attacked should trust their intuition, be loud and fight as hard as possible, respond immediately and hit with an open hand.

Herron said she feels empowered after her recent experience and is still training to run the Seattle Rock and Roll Marathon this summer.

Steiner has an assault record against multiple women dating back to the 1990s, according to authorities.

Steiner is being held in jail on $750,000 bail and faces charges of attempted rape in the second degree and second degree assault, according to court documents. Steiner's public defender did not reply to ABC News' request for comment.