Zheng Jie became the first Chinese player to reach the quarterfinals at the Australian Open after she powered past No. 31 seed Alona Bondarenko of Ukraine 7-6 (4), 6-4 on Sunday.
The victory means that the unseeded Zheng, the 2008 Wimbledon semifinalist, has knocked out seeded players in three consecutive rounds after defeating Maria Jose Martinez Sanchez, the 24th seed, and then upsetting 11th seed Marion Bartoli of France in round three.
She will next play Maria Kirilenko for a place in the semifinals.
"I think everybody has a chance for the semifinal," said Zheng at the post-match press conference.
No. 2 seed Dinara Safina was forced to retire from her fourth-round match with Kirilenko due to what appeared to be a back injury. She was trailing her compatriot Russian 5-4 and 30-40 on serve when she called an end to the match.
The walkover win for Kirilenko, who turns 23 tomorrow, means she progresses to the last eight of a grand slam for the first time in her career.
Meanwhile, Justine Henin beat fellow Belgian Yanina Wickmayer 7-6, 1-6, 6-3 to reach the quarterfinals.
"It's a great feeling to be back, everything is going so well," said Henin, who is playing her first Grand Slam since the Australian Open in 2008 after retirement. "Physically, it's tough as I didn't play for two years, but I love being back on court."
Henin will now play Nadia Petrova in the quarterfinals following the Russian's 6-3, 3-6. 6-2 win over third seed Svetlana Kuznetsova.
On the men's side, Andy Murray, the No. 5 seed, beat American John Isner 7-6 (7-4), 6-3, 6-2 and defending champion Rafael Nadal chalked up a four-set win over Ivo Karlovic from Croatia.
U.S. Open champion Juan Martin del Potro of Argentina, however, lost in five sets to Marin Cilic, the No. 14 seed from Croatia.
Cilic outlasted Del Potro 5-7, 6-4, 7-5, 5-7, 6-3 over 4 hours, 38 minutes to advance to his second straight Grand Slam quarterfinal. He'll face either seventh-seeded American Andy Roddick or No. 11 Fernando Gonzalez of Chile.
(Xinhua News Agency January 24, 2010)