Venus Williams was beaten in the fourth round of the French Open by Russia's Nadia Petrova, 6-4, 6-3 on Sunday.
Williams came into the tournament seeded No 2, behind her sister Serena, but Petrova spoilt the possibility of a sibling showdown in the final.
Petrova has been a nemesis for the Williams family lately -- she beat Serena in the third round at Madrid less than three weeks ago.
Justine Henin rallied in a winner-take-all set that seemed like a final, out-slugging Maria Sharapova 6-2, 3-6, 6-3. The two former No 1s returned to centre court following an overnight suspension of the third-round showdown after two sets.
Then came Williams-Petrova, with both players bundled up on a damp, windy day.
Williams' celebrated corset was under wraps with a long-sleeve top over her black lace outfit while Petrova wore long sleeves and tights under a frilly skirt.
The Russian controlled rallies with steady play from the baseline and finished strong, a problem for her in the past.
She swept the final four games and wobbled only once, shanking an overhead shot when leading love-30 in the final game.
She collected herself and won the final two points, closing out the match with an emphatic forehand winner.
Serena wore her playing outfit while watching her sister's defeat from the stands. They were to team up in a doubles match later on Sunday.
Venus converted only one of seven break-point chances. In the second set she lost serve three times after taking a 2-love lead.
Petrova, seeded 19th, is a two-time semifinalist, but she's into the quarterfinals for the first time since 2005.
The victory was her first against Williams in their five meetings.
Williams came into the tournament with this year's best record on the women's tour, but tricky footing has always made clay her worst surface. In 14 French Open appearances, she reached the semifinals only once -- in 2002, when she lost to her sister in the final. She has advanced beyond the fourth round just once in the past six years.
Joining Petrova in the quarterfinals were No 3 Caroline Wozniacki, No 5 Elena Dementieva and No 17 Francesca Schiavone.
Wozniacki, enjoying her best run at Roland Garros, needed three hours to beat No 14 Flavia Pennetta 7-6 (5), 6-7 (4), 6-2. No 5 Elena Dementieva beat unseeded Chanelle Scheepers 6-1, 6-3. No 17 Francesca Schiavone defeated No 30 Maria Kirilenko 6-4, 6-4.
