Osaka, Japan (Sports Network) - Australia's Samantha Stosur was a winner in quarterfinal action at the HP Open.
The top-seeded Stosur was a 6-2, 6-4 winner over USA's Jamie Hampton.
Stosur was last year's Osaka runner-up to Frenchwoman Marion Bartoli and titled here in 2009.
South Africa's and No. 7 seed Chanelle Scheepers and Britain's eighth-seeded Laura Robson were a pair of upset losers.
Taiwan's Kai-Chen Chang disposed of Scheepers 2-6, 6-1, 6-3, while Japan's Misaki Doi took out Robson 6-4, 3-6, 7-6 (6-4).
Britain's Heather Watson downed frenchwoman Pauline Parmentier 7-5, 6-3 in the other quarterfinal match.
This week's winner will earn a first prize of $37,000.