Robredo came up against an inspired Stepanek

The Spaniard, ranked 11 in the world, lost 6-4 6-2 in his final warm-up event before the Australian Open.

Australian sixth seed Lleyton Hewitt, who is chasing a record fifth Sydney title, beat Nicolas Mahut 6-3 6-4.

Jelena Jankovic seemed untroubled by the leg injury which saw her withdraw from Hopman Cup action last week as she reached the women's quarter-finals.

The Serb recovered from a sloppy second set to defeat France's Tatiana Golovin 6-1 2-6 6-3.

I think I have a game that can get me to win a Grand Slam Ana Ivanovic

Fellow Serb and fourth seed Ana Ivanovic came from 5-2 down in the final set to beat Virginie Razzano of France 6-1 2-6 7-5.

Ivanovic, last year's French Open runner-up and Wimbledon semi-finalist, said she had worked on her fitness harder than ever to make sure she is fully acclimatised to the humid conditions.

606: DEBATE There's a pretty strong field in the Medibank International Raskolnikov.

"This match gives me confidence because I am coming into the new season looking for tough matches and to get through them," she said.

"There are many players who want exactly the same thing, but I think I have a game that can get me to win a Grand Slam."

World number one Justine Henin-Hardenne went through after her Czech opponent Lucie Safarova withdrew with a leg injury before the match.

Second seed Svetlana Kusnetsova, progressed with a 6-3 6-4 win over Shahar Peer, but sixth seed Daniela Hantuchova lost to Nicole Vaidisova 6-4 6-2 and seventh seed Marion Bartoli fell to Francesca Shiavone 2-6 6-3 6-2.