Mauresmo powered past Russian teenager Olga Poutchkova 6-2, 6-2, finding the rhythm she said had eluded her when she first appeared in this year's tournament two days ago.

She broke Poutchkova's serve three times in each set, and remained unflustered by both a controversial line call at the end of the first set and an unexpected loss of two service games to the promising 19-year-old.

"I'm very happy," Mauresmo said. "It's never easy when you go out there and you don't know the player you're up against.

"She was pretty talented and she could really play some great shots so I was very serious tonight and I'm very happy to go through."

Mauresmo will meet Czech Eva Birnerova in the third round, with seventh seed Elena Dementiava and 10th seed Nicle Vaidisova the main potential hurdles in the way of a semi-final berth.

Seven-time Grand Slam champion Williams, a winner in Melbourne in 2003 and 2005, looked out-of-sorts and distracted as she battled to a 7-6 (7/4), 6-2 win over Anne Kremer of Luxembourg.

She constantly hit returns long and committed 33 unforced errors, undermining her dream of winning a third Australia crown on her return to top-level tennis.

Her win set up a third round clash with Russian fifth seed Nadia Petrova, with Williams acknowledging she was rusty and needed have to improve for her toughest test since coming back from injury.

"It's definitely a step up. I feel excited to go into the match. I feel ready," she said.

Petrova, who cruised past Argentine Gislea Dulko 6-1, 6-2, has a 5-1 loss-win record against Williams but they most recently met in 2005. Since then the Russian has improved her world ranking to number six while Williams slipped to 81.

Former US Open champion Svetlana Kuznetsova looked imposing in defeating Australian wildcard Monique Adamczak 6-2, 6-1 to set up an all-Russian clash with Maria Kirilenko.

Third seed Kuznetsova pulled out of the Sydney International last week with respiratory problems and could be heard repeatedly coughing during her match here but said she was feeling better.

"I think it sounds worse than I feel. Last week I was really feeling horrible, but this week I felt better every day," said the 21-year-old from St. Petersburg.

Elsewhere in the women's draw, Serbian eleventh seed Jelena Jankovic beat Spaniard Virginia Ruano Pascual 6-2, 6-2 and France's Tatiana Golovin, seeded 20, crushed Czech Zuzana Ondraskova 6-2, 6-0.