When Sun Yang won the gold medal in the men's 800-metre freestyle at the world championships last week in Shanghai, he did something unusual for the normally reserved Chinese swimming team.

He celebrated with boyish delight.

After the medal ceremony, the 19 year old climbed into the stands to high-five Chinese fans and give away the stuffed animal the medallists receive on the podium.

He then draped himself with a Chinese flag and flashed a giant grin for photographers.

China's swimmers have had a surprisingly strong meeting, winning four golds and 12 medals overall up to yesterday afternoon — putting them just behind the United States on the swimming medal table although they lead the overall table after dominating the diving competition.

But while the team has a number of gold-medal contenders for the London Olympics — the 100m women's backstroke winner, Zhao Jing, and the 200m women's individual medley winner, Ye Shiwen - China does not yet have a superstar, someone on par with Italy's Frederica Pellegrini or Michael Phelps of America.

The charismatic Sun may be on his way there.

He has been the dominant distance swimmer at the worlds, winning the 800m freestyle in a time of 7mins 38.57secs, more than three seconds ahead of Ryan Cochrane of Canada.

The time was also faster than the Australian Grant Hackett's former world record of 7:38.65, which had stood for four years before being eclipsed by Sun's teammate, Zhang Lin, at the 2009 worlds in Rome in a now-banned hi-tech bodysuit.

"Before the competition, I was already looking forward to getting the gold medal," Sun said. "When I touched the final wall, I was so excited, but I still know there are a lot of competitions in the future."

Sun also won a silver in the 400m free and a bronze in the 4x200m relay, and he qualified first yesterday for today's 1,500m freestyle final with a preliminary time of 14:48.13.

Not only is Sun the favourite to win the 1,500m, he could also break Hackett's long-standing world record in that event.

Under the tutelage of Hackett's former coach, Dennis Cotterell, Sun shocked the world at the Asian Games in Guangzhou in China last year by winning the 1,500m in a time of 14:35.43, just under a second off Hackett's 14:34.56 from the Fukuoka, Japan world championships in 2001.

Sun may need to break the record to step out from behind the shadow of his own teammate, Zhang, who became the leader of the men's team after he surprisingly won a silver at the 2008 Olympics and a gold at the 2009 worlds. Even at Sun's news conference following his 800m victory on Wednesday, he was asked as much about Zhang as he was his own race. One Chinese reporter even mistakenly called him Zhang.

"I think I am myself, and Zhang Lin is himself. I don't need to compare myself with others," he said.

"Yes, Zhang Lin won the gold medal before me, but I'm still young. I still have a lot of opportunities in the future."

Sun is beginning to endear himself to the Chinese media after he was criticised for being in tears after nearly all of his races at the Asian Games, which some saw as a sign of immaturity.

But Terry Rhoads, the managing director of Zou Marketing, a Shanghai-based sports consultancy focused on the China market, said Sun still has a long way to go before he supplants the likes of Yao Ming, the recently retired NBA player; Li Na, the French Open tennis championship winner; or Liu Xiang, the gold-medal-winning hurdler.

"Sun needs to first win Olympic gold, set a world record or two, and generally dominate his sport for two Olympics to have a hope of slipping into the A-list," Rhoads said.

"He also needs to show off some English skills with the foreign media and project some of his personality into interviews. Just giving cliches to the media won't satisfy China's sports fans, who are attracted to the rare superstar Chinese athletes who can be colourful and confident, and be among the world's best in their respective sport."

Sun's competitors definitely believe he is a future star of the sport.

Chad La Tourette, the American, said yesterday that he thinks the young Chinese swimmer has a good chance of breaking Hackett's 10-year-old 1,500m record in today's final.

"It was 10 years ago that Hackett got that record. And he's the all-time great," he said.

"We could be turning a new stone with Sun Yang."