At first glance, most would think that a 20-something-year-old girl with a small frame and a sweet smile would be an unlikely candidate to jump into a mixed martial arts (MMA) cage.

This partly explains how Lin Heqin became an instant sensation when she made history by becoming the first Chinese fighter to claim gold at the World MMA Championships, a prestigious nation versus nation combat event. She is also the first woman to be crowned in the tournament.

Dubbed "Wrestling Sister Lin" by her adoring fans, likening her to Lin Daiyu, a beautiful heroine of frailness in the classic Chinese novel "A Dream in Red Mansions", Lin is much more than her looks.

The fierce competitor has fought her way through various MMA tournaments with ten golds on her tally before finally getting into the final at the 2017 World MMA Championships in Astana, Kazakhstan, and winning the gold in the women's 52.2kg category.

Soon after the victory, the avid social media user took to her Sina Weibo account to share her gratitude.

"So excited to win women's first gold in World MMA Championships' history, it's my best wish to make a small contribution to my mother nation, thank you all for your encouragement and support!"

A world champion cheered by thousands in the arena now, Lin didn't start her fighting course expecting the roaring applause.

"I dreamed about becoming a policewoman since childhood, and I used to believe that I could make one if I keep with martial arts training," Lin told China Youth News.

Lin's parents, who were worried about the toughness of the training, didn't nod to the girl's passion at first, but at last gave in to the insistent daughter.

She started with half year's wrestling training, and then moved on to the Chinese free combat, a type of traditional fighting that involves grappling, striking, punching and kicking.

After serving in the People's Armed Police Force for three years, Lin became a professional MMA fighter in 2015 and has since taken up tens of rough, bloody fights behind the cage door.

Injuries are the norm for each bout. As long as she didn't end in knockout, Lin wouldn't be bothered too much.

Lin recalled one training session when she was punched in the nose by a male competitor. After a blacking out for a second, Lin realized her nose was bleeding terribly, and wondered if the nose was crooked. She told herself that she just needed another punch to straighten it back. "I practiced hard in boxing since then so that no one could beat me, it also helps lower the chances of injuries."

Lin knows well that she could take her MMA dream higher.

"Let me take one day off to have a good sleep, and then will start preparing for my next fight on October 28 in Melbourne," Lin wrote on her Weibo Tuesday.