Earlier ninth seed Ai Sugiyama won an all-Japanese battle with Shinobu Asagoe 6-2, 6-3 to advance to the second round of a tournament shorn of top seed Amelie Mauresmo who became the latest big name to withdraw.

In other first round action Russian eighth seed Nadia Petrova eased past American wild card Lisa Raymond 6-4, 6-3 and Paola Suarez of Argentina outlasted Croatia's Jelena Kostanic 6-3, 3-6, 6-4.

Mauresmo, who has not trained since picking up a hamstring injury in the final of Filderstadt ten days ago, withdrew as a "precautionary measure", according to her press agent.

The Frenchwoman also pulled out of last week's Moscow tournament where she lost her world number one ranking to Lindsay Davenport.

Her withdrawal was a blow to organisers coming after number two seed Davenport, who is suffering from a cold, and fellow American Serena Williams, the fifth seed, a recurring knee injury.

"I think if this tournament was next week I would have been able to play it," said Mauresmo.

"I hesitated before pulling out because I really wanted to play. But I saw the doctor again on Monday and had some more exams and we made the decision because he thinks it is still dangerous to play matches.

"Even if I hadn't needed to play until Thursday it would still have been too early. It's a very frustrating decision, but it's a safe one. It could have got worse and it would have been difficult for me to finish the season."

Venus Williams, seeded seven, would not have relished the prospect of facing the 19-year old Sprem. At the German Open in May the teenager led Williams 4-1 in the third set of their semi-final, and then claimed a 7-6, 7-6 second round victory over her at Wimbledon.

This time the American was never threatened against an aggressive but careless opponent who often overhit the ball. Sprem also had difficulty with her serve at times, double-faulting twice as she dropped serve in the opening game to give Williams all the encouragement she needed.

In the second set, Sprem failed again to win either of the two break points she held. The first came after Williams had broken for 2-1 by forcing a forehand error, but Sprem netted the ball. Williams then broke to love to lead 4-1 and saved a break point in the next game with an ace.

"I don't think she necessarily played her best today, but she's a very good player," said Williams.

"My game was nice. I was serving well, returning well, just an all-around good game. A lot of pace. That's one of my strengths, to use my pace and power to dictate."

Sugiyama dominated early in her match as Asagoe failed to even earn a game point on her serve in the first set.

The second set was more competitive, with Asagoe holding serve and then breaking to lead 2-1 when Sugiyama netted a double-handed backhand after a furiously-contested rally.

But Sugiyama levelled at 2-2 when Asagoe struck her third double-fault, and she then earned a vital second break to lead 5-3 after Asagoe made a backhand error.

Even then, Sugiyama had to battle to close out the match, escaping a break point when Asagoe netted a backhand.