Lu Yen-hsun, Taiwan's top-ranked tennis player, advanced to the semifinals of the Status Athens Open Friday with a flawless 6-4, 6-1 victory over Japan's Yuichi Sugita. The eighth-seeded Lu has yet to lose a set in his first three matches at the 85,000 euro ATP Challenger event and remained sharp against his Japanese quarterfinal opponent, winning the match without ever facing a break point. Lu, ranked 102nd in the world, got in an uncharacteristically high 77 percent of first serves and broke Sugita four times to coast to victory in just over an hour. He will now meet world No. 257 Gilles Muller of Luxembourg in Saturday's semifinals, as he pursues his first tournament title since winning another Challenger event (second-tier events on the men's tennis tour) in South Korea last November. Lu reached a career best ranking of 55 last June, but it has since tumbled to around 100 because he has played more main ATP Tour events against the world's best players since the middle of last year, with mixed results. Teamed with Rik de Voest of South Africa, the 26-year-old Taiwanese has also reached the semifinals of the doubles event in Athens, after defeating top seeds Leos Friedl and David Skoch of the Czech Republic 6-1, 6-0 on Thursday. 