Saori Obata beat Japanese compatriot Ai Sugiyama 6-4, 6-4 in the second round of the women's singles Thursday at the Australian Open, advancing to the third round of a Grand Slam tournament for only the second time in her career.

News photoSaori Obata raises her arms in celebration after beating Ai Sugiyama in the second round of the Australian Open in Melbourne. Obata won 6-4, 6-4.

Obata, who is ranked 55th in the world, took advantage of service errors by the world No. 9 in the first set at Melbourne Park and threatened with net approaches while Sugiyama wasted points by committing 48 unforced errors to Obata's 29.

Obata carried the rhythm through the second set to get off to a 4-0 run before sealing her first victory against Sugiyama after four head-to-heads.

"I had nothing to lose, so I wanted to see how well I'd be able to play against a top-10 player, not necessarily just Sugiyama," said Obata, who will be making her first third-round singles appearance in a Grand Slam since last year's U.S. Open.

"I tried to go aggressive from the start, but I couldn't find my pace and all my shots were powerless," said the eighth-seeded Sugiyama.