Fifth-seed and Japanese number one Ai Sugiyama comfortably beat compatriot Shinobu Asagoe 6-4 6-1 in the first round of Tokyo's Princess Cup on Tuesday.

In a match-up between Japan's top two female players, Sugiyama recovered from service breaks in both sets to move easily into the second round.

In another first round match on Tuesday, Russia's Elena Likhovtseva defeated 1994 Wimbledon champion Conchita Martinez 6-2 4-6 6-2.

Sixth seed Tatiana Panova of Russia was leading 2-1 against Henrieta Nagyova of Slovakia when rain halted play.

World number one Serena Williams, defending champion Jelena Dokic of Yugoslavia, Kim Clijsters of Belgium and Anna Smashnova of Israel all received first round byes.

First round results from the Princess Cup:

E Likhovtseva (Rus) bt C Martinez (Spa) 6-2 4-6 6-2
(5) A Sugiyama (Jpn) bt S Asagoe (Jpn) 6-4 6-1
(6) T Panova (Rus) leads H Nagyova (Svk) 2-1 (rain stopped play)