Zheng Jie of China returns a shot to Tsvetana Pironkova of Bulgaria during a match of the first round of the New Haven Open tennis tournament at Yale in New Haven, the U.S., on Aug. 21, 2012. Zheng Jie won 2-0. (Xinhua/Wang Lei)

Zheng Jie of China returns a shot to Tsvetana Pironkova of Bulgaria during a match of the first round of the New Haven Open tennis tournament at Yale in New Haven, the U.S., on Aug. 21, 2012. Zheng Jie won 2-0. (Xinhua/Wang Lei)

 Zheng Jie of China returns a shot to Tsvetana Pironkova of Bulgaria during a match of the first round of the New Haven Open tennis tournament at Yale in New Haven, the U.S., on Aug. 21, 2012. Zheng Jie won 2-0. (Xinhua/Wang Lei)

Zheng Jie of China returns a shot to Tsvetana Pironkova of Bulgaria during a match of the first round of the New Haven Open tennis tournament at Yale in New Haven, the U.S., on Aug. 21, 2012. Zheng Jie won 2-0. (Xinhua/Wang Lei)

Zheng Jie of China returns a shot to Tsvetana Pironkova of Bulgaria during a match of the first round of the New Haven Open tennis tournament at Yale in New Haven, the U.S., on Aug. 21, 2012. Zheng Jie won 2-0. (Xinhua/Wang Lei)

Zheng Jie of China returns a shot to Tsvetana Pironkova of Bulgaria during a match of the first round of the New Haven Open tennis tournament at Yale in New Haven, the U.S., on Aug. 21, 2012. Zheng Jie won 2-0. (Xinhua/Wang Lei)