Paris - Venus Williams's 17th French Open ended in the second round on Wednesday, robbing the tournament of a potential clash against sister and world number one Serena.
The 33-year-old Williams lost 2-6, 6-3, 6-4 to Slovak teenager Anna Schmiedlova who was just a month old when the American made her professional debut back in 1994.
Had Venus triumphed, she could have faced top seeded Serena in the third round.
The defending champion was playing Spain's Garbine Muguruza later on Tuesday.
"It's the biggest win of my career," said 19-year-old Schmiedlova who had lost to Venus in straight sets in Miami this season.
"I have big respect for her. She's a great player and I still cannot believe I won."
Defeat for Williams, the 29th seed, meant she has now failed to get beyond the second round in Paris on her last three visits.
She was undone by 47 unforced errors on a half-full Philippe Chatrier court and despite saving two match points it was all too much for mother Oracene who was caught on TV napping as Venus slipped to defeat.
Schmiedlova, playing at a career high ranking of 56, said she will not be intimidated by possibly facing Serena in the next round.
"I want to beat both of the sisters," she said.
Later Wednesday, second seed Novak Djokovic, the 2012 runner-up who needs a French Open title to complete a career Grand Slam, faces Jeremy Chardy of France for a place in the last 32.
Djokovic holds an 8-0 career lead over the world number 42 with his stranglehold illustrated by never surrendering a single set to Chardy.
However, the Frenchman came into Roland Garros with a win over Roger Federer in Rome under his belt.
Federer, the fourth seed, looks to claim his 60th win at the tournament when he takes on 21-year-old Argentine qualifier Diego Sebastian Schwartzman.
Maria Sharapova, the seventh seeded 2012 champion, faces Bulgaria's Tsvetana Pironkova, a Wimbledon semi-finalist in 2010.
Latvian 18th seed Ernests Gulbis eased past Argentine qualifier Facundo Bagnis 6-2, 7-5, 6-0 and will next face Czech veteran Radek Stepanek who knocked out Russian 15th seed Mikhail Youzhny 6-0, 6-3, 3-6, 6-4.
In a first round match held over from Tuesday night, American Steve Johnson completed a 4-6, 6-7 (7/9), 7-6 (7/3), 6-3, 6-3 comeback win over French world number 406 Laurent Lokoli.
The teenage Frenchman had two match points in the third set.
Italian women's 12th seed Flavia Pennetta was knocked out by Sweden's Johanna Larsson who now faces 18th seed Eugenie Bouchard.
The highly-rated 20-year-old Canadian, who made the Australian Open semi-finals this year and captured her first title in Nuremberg at the weekend, put out Germany's Julia Goerges 2-6, 6-2, 6-1.Results on Wednesday at the French Open, the fourth day of the season's second Grand Slam tournament at Roland Garros (x denotes seeded player):
Tomas Berdych (CZE x6) bt Aleksandr Nedovyesov (KAZ) 6-7 (4/7), 6-4, 7-5, 6-3
Roberto Bautista Agut (ESP x27) bt Benot Paire (FRA) 6-4, 7-6 (7/4), 6-2
Tommy Robredo (ESP x17) bt Kenny De Schepper (FRA) 6-2, 6-3, 6-3
Radek Stepanek (CZE) bt Mikhail Youzhny (RUS x15) 6-0, 6-3, 3-6, 6-4
Ernests Gulbis (LAT x18) bt Facundo Bagnis (ARG) 6-2, 7-5, 6-0
Dmitry Tursunov (RUS x31) bt Sam Querrey (USA) 6-4, 7-5, 6-1
Roger Federer (SUI x4) bt Diego Schwartzman (ARG) 6-3, 6-4, 6-4
Milos Raonic (CAN x8) bt Jir Vesel (CZE) 7-6 (7/4), 6-4, 6-1
Gilles Simon (FRA x29) bt Alejandro Gonzlez (COL) 6-4, 6-0, 6-2
Marcel Granollers (ESP) bt Aleksandr Dolgopolov (UKR x20) 1-6, 3-6, 6-3, 6-0, 6-2
Martin Klizan (SVK) bt Robin Haase (NED) 6-1, 3-6, 6-1, 1-6, 7-5
Jo-Wilfried Tsonga (FRA x13) bt Jurgen Melzer (AUT) 6-2, 6-3, 6-4
Jerzy Janowicz (POL x22) bt Jarkko Nieminen (FIN) 7-6 (7/4), 7-6 (7/4), 6-4
Marin Cilic (CRO x25) bt Tobias Kamke (GER) 6-3, 3-6, 6-3, 6-0
Novak Djokovic (SRB x2) bt Jrmy Chardy (FRA) 6-1, 6-4, 6-2
Steve Johnson (USA) bt Laurent Lokoli (FRA) 4-6, 6-7 (7/9), 7-6 (7/3), 6-3, 6-3
Garbie Muguruza (ESP) bt Serena Williams (USA x1) 6-2, 6-2
Anna Schmiedlov (SVK) bt Venus Williams (USA x29) 2-6, 6-3, 6-4
Dominika Cibulkova (SVK x9) bt Tamira Paszek (AUT) 6-3, 6-4
Carla Surez (ESP x14) bt Timea Bacsinszky (SUI) 7-5, 1-6, 6-4
Johanna Larsson (SWE) bt Flavia Pennetta (ITA x12) 5-7, 6-4, 6-2
Eugnie Bouchard (CAN x18) bt Julia Grges (GER) 2-6, 6-2, 6-1
Daniela Hantuchova (SVK) bt Claire Feuerstein (FRA) 6-1, 6-4
Angelique Kerber (GER x8) bt Varvara Lepchenko (USA) 6-2, 7-5