SHANGHAI - The "human fish", also known as Michael Phelps, edged out his rivals over the final 50m to claim his first gold medal of the Shanghai World Championships in the 200m butterfly on Wednesday.

Phelps, who finished in one minute, 53.34 seconds, outperformed Japan's Takeshi Matsuda by 0.67 sec while China's Wu Peng finished third (1.33 sec behind the winner).

"My first worlds title in this event came in 2001. It's been 10 years and I've been able to keep (the title) straight through. I felt like kind of getting back (to top form) tonight," the American said.

"In the last 100m of the race, especially the last 25m, I didn't feel like I was dying or feel like I could barely get my arms out of the water or there was a piano on my back," Phelps, the four-time 200m fly world champion, told a packed mixed zone after the race.

Stressing he was still "not in the best shape", Phelps said he was thrilled to retain the title in his favorite event.

"My brand is the butterfly event. Being able to get it back and keep it (the title), I know what I have to do over the next year. I am confident of being where I want to be. I am very pleased that I am heading in the right direction."

After wrapping up a history-making eight gold medals at the Olympic Games in Beijing in 2008, the American superstar swimmer lost some of its motivation.

However, he is refocused on next year's Olympics in London and is using Shanghai as a key part of his build-up to a third Olympic campaign.

"I actually wrote down in my journal all the events and results that I wanted to do at this meet. So far I am on pace to do it. And I know there is a lot more I can do (before the London Games)," said the 26-year-old.

The bronze winner, Wu, who stunned Phelps twice in the event during his training program in the United States this April, was full of praise of the "fastest swimmer on the planet".

"Those two wins didn't mean anything. He was in poor form then and he proved he is still the fastest today," said Wu.

"I felt good in the big event tonight; my time was OK. I will mainly focus on enhancing my stroke's strength and speed when I go back to train in the US. I feel confident about next year's London Olympics after this trial here," he said.

China Daily