American Robby Ginepri moved easily into the Japan [ Images ] Open quarter-finals with a 6-4, 6-4 victory over Luxemburg's Gilles Muller on Thursday.

The third seed showed glimpses of the form that took him to the U.S. Open semi-finals last month, wrapping up victory in 70 minutes.

"I thought I returned extremely well, which helped me get into a lot of his service games, and that won the match," said Ginepri, who lost in five sets to Andre Agassi [ Images ] at the year's last grand slam.

"I don't feel as sharp as I did in the summer but that's going to change shortly."

Ginepri, who lost to British teenager Andy Murray [ Images ] in the quarter-finals in Bangkok last week, will play Germany's [ Images ] Bjorn Phau in the last eight. Phau thrashed 10th seed Kenneth Carlsen of Denmark 6-1, 6-2.

Second seed Radek Stepanek beat fellow Czech 7-5, 6-4 in a second round match, and American Taylor Dent, seeded fourth, overpowered Russia's [ Images ] Dmitry Tursunov [ Images ] 7-3, 7-6.

Top seed Mariano Puerta, who on Wednesday denied a report he had tested positive for a banned substance at this year's French Open [ Images ], plays Marcos Baghdatis [ Images ] of Cyprus in the evening session.