Tennis' popularity the biggest victory

Even the most devoted Chinese sports fans could barely recognize Zheng Jie and Yan Zi four years ago, but now the duo needs bodyguards at training camp.

Coming into the Games among the most popular of China's 639 Olympic athletes, the women's tennis players are aiming to win both singles and doubles medals.

But regardless of whether they succeed or not, they have already chalked up a significant win by lifting tennis to national prominence.