China's Zhao Jing celebrates after winning gold in the final of the women's 100-meter backstroke at the FINA World Championships in Shanghai on Tuesday. Zhao won by 0.01 sec. Cui Meng / China Daily

Chinese 20-year-old girl Zhao Jing steal spotlight at the 14th FINA World Championships on Tuesday as the backstroke talent upset American favourite Natalia Coughlin and delivered a last-gasp victory in the women's 100m backstroke.

Zhao, winner and world record holder of the 50m backstroke at 2009 Rome worlds, staged a strong comeback with the powerful stroke in the final 20m. She overtook the lead with a minor advantage to touch the wall first in 59.05 seconds, her personal best, sending red-clad and drum-beating fans into celebration in the second final of the night.

Coughlin, the Olympic gold medalist of the discipline, led the first 50 meters but was exceeded by Zhao and Russian Anastasia Zueva in the final spurt. Zueva was 0.01 second behind for the silver, followed by Coughlin at 59.15.

"The gold medal has significant meaning to me. It is definitely a huge boost to my confidence in the build-up to the London Olympic Games," said Zhao, who burst into tears after winning the title.

"I didn't swim at my full strength in the semifinal. And after the semi, my coach and I studied video replays carefully and he asked me to pay more attention to details," added the winner, who ranked third in the semifinal.

Zhao owed her victory to the trianing in Australia. "It's my personal best, which is not easy," said the Hubei native. "The eight-week training in Australia helped me a lot."

Zhao changed to 100m backstroke after 2009. "The gold was different to me," she said. "Last time I won the 50m gold, and this time it's the 100m. And next year is the Olympic Games and the worlds is for the preparation."

The swimming talent jumped to fame after winning gold medal and breaking Asian record of the 50m backstroke at 2006 Doha Asian Games, and she broke the 100m backstroke Asian record at the 2008 National Championships.

However Zhao experienced a waterloo at the Beijing Games as she was disqualified in the 100m backstroke semifinal due to false start.

"I know that a lot of people think I didn't have good skills and mental strength before I win," she said. "So I want to prove myself today. Ye Shiwen also win the title after a last surpass. I was a little nervous in the final but I controlled myself."

"I believe that my gold medal denies the rumor," she said.

After the Rome worlds, Zhao created new Asian record in 100m backstroke at National Games 2010 and won 100m and 200m backstroke golds, but she was not happy as she failed to break the world record.

Zhao managed to do it at the 2009 short course World Cup in Stockhelm where she break the short course world record twice in 50m backstroke. She also renewed the 100m individual medley short course world record at Stockhelm.

Zhao will also take part in the women's 200m backstroke at Shanghai.

"I will do some adjustment and get prepared for my 200m race," said Zhao.