By Ian Ransom

SYDNEY (Reuters) - As the humble daughter of factory workers at a Bangkok sweet-maker, badminton was a ticket out of poverty for Ratchanok Intanon, who hopes winning gold at the Rio Olympics might inspire more Thai girls to chase their dreams.

The 21-year-old will be among Thailand's main medal hopes in Brazil and one of the chief threats to China's chances of defending their astonishing sweep of all five badminton titles at the London Games.

Ratchanok is spurred by a painful memory of London, where, as a teenage sensation set to rock the Chinese establishment, she choked in a quarter-final when poised to defeat the tournament second seed, Wang Xin.

"Actually I think I had a chance to win or (be) close to the medals," Ratchanok told Reuters ruefully in an interview in Sydney on Tuesday.

"But I think I lost with the experience, because that time I was still young and she was also good, world class.

"So maybe... mentally she was better than me.

"That time, I didn't feel good after losing. I felt like I didn't want to train again. I felt I didn't want to play badminton again.

"But I had support. My family, who love me, just said that it's okay, you still have time. Just learn more."

Ratchanok did not wallow for too long.

The following year, she became badminton's youngest world champion at the age of 18 when she stunned Olympic champion Li Xuerui in the final of her home tournament in Guangzhou.

Ratchanok may face Li this week at the Australian Badminton Open, the last major meeting before the Olympic tournament starts Aug. 11.

CONFIDENT OF SUCCESS

Ratchanok has had injury troubles and dips in form since her world title but has been in ominous condition in recent months, capturing three consecutive Superseries tournaments to rise to the world number one ranking in April.

She has since conceded it to Spain's two-time world champion Carolina Marin but her brief spell at the top sent Thailand into a frenzy.

Rather than shy away from the hype, Ratchanok has embraced the expectation.

"I hope that I can get the gold medal for Thailand," said Ratchanok, standing on a terrace at her hotel adjacent to Olympic stadiums built for the 2000 Sydney Games.

"It's not too difficult for me and I believe that I can do it."

Ratchanok had an unusual route into badminton, being handed a racquet at the age of six and told to go play outside the factory where her parents worked making sweet Thai desserts.

Her tournament winnings and endorsements have been enough to help her parents start their own food business, while her achievements have won her friends in high places.

After becoming Thailand's first world number one, Ratchanok played a game with Prime Minister Prayuth Chan-ocha during a visit to government house.

During the meeting she asked him if her Chinese coach's application to become a Thai citizen could be expedited, local media reported.

Xie Zhuhua, who once battled China's current head coach Li Yongbo during competition in the 1990s, has coached Ratchanok since her junior days and is seen as key to her ability to unlock the games of her Chinese rivals.

"He just takes care of me like I'm his daughter, because he also doesn't have (one)," Ratchanok said of their special relationship.

"He loves me like a daughter and takes care of me. For me, he's like a second father, so I just do my best."

(Editing by John O'Brien)