AUSTRALIAN Casey Dellacqua's strong form ahead of the US Open continued with an upset second-round win over Yanina Wickmayer at the WTA Texas Open.
The qualifier beat the Belgian fourth seed 6-4, 6-3, setting up a quarter-final against Canada's Aleksandra Wozniak, who later downed countrywoman Eugenie Bouchard 6-2, 6-2.
The hardcourt tournament serves as a warm-up event for the US Open, starting next week in New York.
Second-seeded Jelena Jankovic and No. 3 Roberta Vinci have also advanced to the quarter-finals.
Jankovic, the former world No. 1 from Serbia, defeated Arantxa Rus of the Netherlands 7-6 (7-5), 6-2 to line up a quarter-final clash against eighth-seeded Sorana Cirstea of Romania, a 6-1, 7-5 winner over France's Alize Cornet.
Italy's Vinci encountered little resistance in a 6-2, 6-3 victory over Slovakia's Polona Hercog. She'll face seventh-seeded Chanelle Scheepers of South Africa, who beat New Zealand's Marina Erakovic 6-4, 7-6 (7-3).
Vinci said she was feeling confident with the US Open due to start on Monday on the hard courts of Flushing Meadows.
''I played good tournaments in Montreal and Cincinnati,'' Vinci said. ''I like to play on hard courts. I like to play on fast courts. I play a lot of slice, probably that's why I play on fast courts.''
Sixth-seeded Peng Shuai of China moved safely through with a 6-4, 6-2 victory over France's Pauline Parmentier.
Peng will face wildcard Bojana Jovanovski of Serbia, who beat Croatian Mirjana Lucic 7-6 (7-5), 6-2.
Meanwhile, top-seeded Frenchman Jo-Wilfried Tsonga launched his campaign at the ATP's Winston-Salem hardcourt tournament in North Carolina with a straight-sets victory over Thomaz Bellucci.
The world No. 6 converted just one of his nine break-point opportunities, but saved all five that he faced to beat the Brazilian 6-3, 7-6 (7-3). Tsonga was one of 16 seeded players to enjoy a first-round bye. In the third round, he'll face Ukrainian qualifier Sergiy Stakhovsky - a 6-2, 6-3 winner over Spain's Pablo Andujar.