SINGAPORE - When Constance Lien first signed up with Evolve Mixed Martial Arts about three years ago, she was offered a welcome gift of either muay thai gloves or a Brazilian jiu-jitsu gi (uniform). She chose the gloves, thinking she would make a fool of herself learning BJJ.

This was despite her father urging her to take home the gi, although about a month later, the former national swimmer changed her mind as "all my friends started going to BJJ and stopped muay thai".

Peer pressure put the now-19 year-old on the path to success, as she clinched the women's blue belt featherweight (under 58.5kg) world title on her debut outing at the World IBJJF Jiu-Jitsu Championships in California on Thursday.

Cheered on by a group of supporters that included her father and grandmother at the Walter Pyramid in Long Beach, Lien beat Jaine da Silva Fragoso in the final to clinch the gold.

But the Singaporean, who won a ju-jitsu silver at last year's Asian Games, described her quarter-final against Brazilian Julia de Jesus Alves as the toughest.

"She won the absolute category (where competitors of the same belt colour take on one another regardless of weight class) at this same competition last year and she's tough - I almost lost in the last 10 seconds against her," said Lien, who last month was awarded the Sportsgirl of the Year accolade at the Singapore Sports Awards.

"It came down to who wanted it more... I had to sweep her to win and I did, and that was the best moment after winning the title."

Winning that bout gave her the strength to hang on in the final, where she was almost submitted by her Brazilian opponent Fragoso in the last 20 seconds.

"I fought hard for the five rounds before this, I wasn't going to give up in the last 20 seconds and I was (thinking) there's no way I'm going to tap to this," added Lien, who was The Straits Times' Star of the Month last August.

"It's always been my dream to come here as a blue belt and win the world championships... I just started crying the moment I won and I couldn't stop."

Paying tribute to her family, coaches and sparring partners, she said: "There were people just cheering me on every single day and every time I said I wanted to quit during training because it was too painful, my training partners and coaches pushed me through it.

"Without them I wouldn't have got to where I am, and those days made (this win) more meaningful."

Her Evolve MMA trainer Teco Shinzato praised her work ethic and said: "She comes in every day with a great attitude, wanting to learn and help her teammates.

"She has a very bright future in BJJ and I'm very excited to see her continued success."

Lien's celebration came in the form of a double cheeseburger, fries and two milkshakes from In-N-Out Burger but she has vowed not to go overboard with the feasting as her next goal is to win a SEA Games ju-jitsu gold.

She aims to qualify for the Nov 30-Dec 11 Games when she competes at the July 14-21 Ju-Jitsu Asian Championships in Ulaanbaatar, Mongolia.

"In Mongolia and at the SEA Games we'll be fighting athletes of the same weight but they could have different coloured belts, so I could be fighting people of a higher standard or with more experience," explained Lien.

"I just got promoted to the purple belt and it's a whole new level... you can never stay stagnant in this sport, and I now have bigger dreams ahead."