Defending French Open champion Jelena Ostapenko lost her opening match to Ukraine's Kateryna Kozlova at the season's second major.
Seven-time major champion Venus Williams was beaten 6-4, 7-5 by 85th-ranked Wang Qiang of China.
She is only the second reigning women's champion to exit in the first round of the French Open a year later - it happened to 2005 victor Anastasia Myskina, too - and only the sixth at any major tournament in the professional era.
Kozlova, competing with a large, weeping blister on her heel which caused her to take a medical break at the end of the first set, was well worth the victory, playing with power and composure, in contrast to the flustered champion. Ostapenko, the defending champion at Roland Garros, lost in straight sets. Kozlova, ranked 66, makes it an unhappy hat-trick for the 20-year-old.
Ostapenko's eyes searched the coach's box at every opportunity, but could find no answers as she checked out early.
That came in Nuremberg last week, her first appearance on the tour since February because of a right knee injury.
"One of the blisters was worse than the others, it was very bloody".
The match umpire then asked both players before the third set if they wanted to continue, and they consented.
Kozlova will face either former world number one Victoria Azarenka or Katerina Siniakova of the Czech Republic for a place in the last 32.
Wang avenged her loss to the ninth-seeded Williams in the first round at Roland Garros previous year. "I feel good, and today was a good start to the tournament, and I'm happy the way it's going so far", said the beanpole German.
"I like to think", she said, "that I win all my matches if I'm playing well".
Seven-time major victor Venus Williams suffered back-to-back opening round exits at the Slams for the first time in her 21-year career.
Errani lost to 32nd-seeded Alize Cornet of France 2-6, 6-2, 6-3, while Schiavone was beaten by Viktoria Kuzmova 7-6 (2), 7-6 (2).
- Malaysia drops high-speed rail project
- Xiaomi Mi 8 will feature iPhone X-like AR emoji
- Houston Rockets: 3 takeaways from Game 6 vs. Warriors
- New Zealand to kill 150000 cows to end bacterial disease
- Remnants of Subtropical Storm Alberto could reach Upstate NY this week
- Poland seeks permanent USA troop presence, offers financing
- Prince Harry And Meghan Markle Heading To Canada For Their Royal Honeymoon
- Mother of festival death teenager Georgia Jones warns of drug danger
- Wildwood Police Wrestle 20-Year-Old Emily Weinman On New Jersey Beach
- Irish scientists discover 125 million year-old dinosaur dandruff Irish News