All seeds victorious on Day 4 in Stuttgart, including Jankovic

All of the seeds in action on Day 4 were victorious, including Jelena Jankovic, who will return to the No. 1 spot next because Serena Williams lost her opening match on Wednesday.

Jankovic, seeded second, had a first round bye, and won her opening match in easy straight sets to Ukrainian Alona Bondarenko, 62 60. Jankovic is now 9-0 in head-to-head results against Alona.

Other seeds who cruised through were No. 3 seed Dinara Safina, who won her match to Tsvetana Pironkova, 61 76(6); No. 6 seed Venus Williams won her match to Kateryna Bondarenko, 64 62; and No. 7 seed Vera Zvonareva ousted Marion Bartoli, 62 60.

In a match of unseeded players, Nadia Petrova routed Patty Schnyder in straight sets 64 61.

No. 4 and 5 seeds through to quarters; Rus through to second round

The quarterfinals of the Tashkent Open are partly set, as No. 4 seed Sabine Lisicki and No. 5 seed Magdalena Rybarikova both reserved spots in the quarters with straight set wins.

"I'm now feeling very comfortable and more confident and hitting the ball better," Lisicki said after her 75 61 defeat of Russian qualifier Alexandra Panova. "I was a bit rusty in the first set, which could have been 64, but as the match progressed I'm feeling comfortable and look forward to doing well."

2007 Junior Wimbledon champion Urzsula Radwanska will face German Lisicki, after the Pole dispatched Sofia Shapatova of Georgia, 75 62.

Ioana Raluca Olaru also has a spot in the quarters, after she ousted Ksenia Palkina, who beat No. 2 seed Olga Govortsova on Tuesday, 26 63 62.

Junior No. 1 Aranxta Rus of the Netherlands fought back from a set down to win to 36 62 61

Israeli ousted in second round; No. 2 seed advances

No. 6 seed Shahar Peer had the honour to shake the hand of legend Kimiko Date Krumm at the end of her first round match victory, but it wasn't like that against her second round opponent, as she flew out of the AIG Japan Open in three sets.

Peer failed to pass her second round test against lucky loser Jarmila Gajdosova, as she lost, 57 61 76(9).

No. 2 seed Anabel Medina Garrigues didn't achieve the same fate as Peer, as she won her first round match to Yung-Jan Chan, 36 63 63.

Other seeds included in the winning circle on Wednesday were No. 5 seed Kaia Kanepi, who won her second round match to Yanina Wickmayer, 36 61 60, and joining the Estonian was No. 7 seed Tamarine Tanasugarn, who won her second round match to Camille Pin, 62 62.

Biggest upset in Stuttgart created

Jelena Jankovic has only been No. 1 for a week, and she will return to the spot next week, after Serena Williams, this week's No. 1, was ousted on her debut match by Chinese Li Na in three thrilling sets.

Na had an easy first round win, but the win against the American was much tougher. Na made history for herself and her country after the win, as she is only the second woman to win to the reigning No. 1, after Jie Zheng dispatched Ana Ivanovic at Wimbledon. Na won 06 61 64.

"I didn't play well at all," said Williams, who was coming off her ninth Grand Slam singles title. "I started off really solid then my level dropped. In the third set she played really well and I didn't, and that was the difference. If you make that many unforced errors like I did at the end, you don't deserve to win the match."

"To be quite honest I don't deserve it playing like that; I have to step it up and I will," Williams said about the No. 1 spot. "I've been No.1 before and held it for a long time, so I know how that feels. At this stage of my career the titles are what matter to me - like this tournament. Winning the US Open this year and returning to No.1 after five years was an absolute highlight. I want to try and finish the year in that position."

"After I lost the first set I checked the clock and saw it was only 20 minutes, so I told myself I had to make it at least an hour," Li said. "Of course I'm very happy about my win today, and for both of my wins over the Williams sisters this year."