Serena Williams and Zheng Jie have met only once before - on the grass of Wimbledon in 2004.
Wimbledon semi-final: Serena Williams v Zheng Jie
Serena Williams and Zheng Jie have met only once before - on the grass of Wimbledon in 2004.
On that occasion, Williams won their first-round match 6-3 6-1 and went on to lose in the final to Maria Sharapova.
Williams, the world number six, reached the final three years running from 2002 to 2004, winning the title twice.
The 26-year-old American has eight Grand Slam titles, having won the Australian Open three times, the US Open twice and the French Open once.
She held all four Grand Slam titles at the same time when she won the Australian Open in 2003.
By contrast, this is the first time Zheng has been beyond the fourth round of any Grand Slam.
Her previous best performance was reaching the fourth round on her debut at Roland Garros in 2004.
She did not win a single Grand Slam match in 2007, going out in the first round in Melbourne and Paris before missing three successive majors because of injury.
The 24-year-old from Chengdu has won three WTA Tour titles in her career - compared to 31 for Williams - and has a highest ranking of 27 in August 2006.
Head-to-head record:
2004 Wimbledon (Grass)
Winner: WILLIAMS 6-3 6-1
