Japan's top tennis player Ai Sugiyama beat Croatian Karolina Sprem in straight sets Wednesday to grab a spot in the quarterfinals of the women's singles competition at the Athens Olympics.

Sugiyama, ranked 13th in the world and seeded eighth in the Games, beat her opponent 7-6 (8-6), 6-1 in 76 minutes at the Olympic Tennis Centre to advance past the third round for the first time in three Olympic appearances.

In the previous two Olympics, Sugiyama lost in the first-round singles and second-round doubles competitions in Sydney four years ago and lasted only up to the third round in singles in 1996.

Sugiyama also made the last eight in the doubles competition after partnering Shinobu Asagoe to a 6-3, 7-5 win over Sprem and Jelena Kostanic.

Akiko Morigami and Saori Obata, however, fell 6-4, 6-2 to Argentine duo Paola Suarez and Patricia Tarabini.