Top seed Jelena Jankovic confidently advanced at the Toray Pan Pacific Open, while fellow Serb Ana Ivanovic, seeded second, lost the first match she played after her shocking defeat at the US Open.

Jelena Jankovic cruised past Italian Flavia Pennetta 6-2 6-1 to book her place in the Tokyo quarterfinals where she’ll face fifth seed Svetlana Kuznetsova of Russia who defeated Japan's Ayumi Morita 6-1 6-1.

Current number two in the world, Jankovic, has a chance to return to the top of the rankings if she wins the Toray Pan Pacific Open.

Ana Ivanovic was upset by Nadia Petrova 6-1 1-6 6-2. Not a great promotion of her new Yonex racquet.

In the first set Ivanovic’s serve was broken three times, while she herself earned no break points. The second set was the same story, only the players exchanged their roles. The world number 20 Petrova pressured unprepared Ivanovic in the decider and the Serb succumbed after an hour and 41 minutes.

The world number three will now fly to Beijing for next week's China Open. (photos: Getty Images)

Slovakia's Dominika Cibulkova rallied to defeat former world number one Amelie Mauresmo of France 0-6 6-1 7-6 (8) in the first round of the Toray Pan Pacific Open in Tokyo.

Despite taking the first set without losing a game, leading 4-1 in the tiebreaker, and having four match points, Mauresmo was defeated by the Slovakian teenager.

"It's always frustrating to lose a match when you have match points and can't close it out," said the Australian Open and Wimbledon champion Mauresmo. "I let her get back into the match in the second set and it's disappointing to lose like that."

As for the fallen seeded players in the first round, eighth seed Anna Chakvetadze was upset by Kaia Kanepi of Estonia 6-4 3-6 6-3, while Francesca Schiavone stunned seventh seed Daniela Hantuchova 6-1 7-5.

Top seed Jelena Jankovic has a bye into the second round, as well as fellow Serb Ana Ivanovic, who is number two seed. (photo: cibulkova-dominika.com)

World number three Ana Ivanovic will begin this week’s Toray Pan Pacific Open in Tokyo with a new Yonex racquet produced specifically for her, no other tennis pro will use it. The 20-year-old tennis star from Serbia will also start using an exclusive new racquet bag.

The racquet, named the RQiS 1Tour XL, will go on global sale to the public shortly.

You can see the racquet bag after the cut. Read more »