Aryna Sabalenka became the sixth top-10 women's seed to exit the French Open's opening week as she fell to an inspired Anastasia Pavlyuchenkova in Paris.
But she was whitewashed in the deciding set as Pavyluchenkova won 6-4 2-6 6-0.
Pavlyuchenkova will face Victoria Azarenka in the last 16 after the 15th seed dominated Madison Keys 6-2 6-2.
Two-time Grand Slam champion Azarenka punished a ragged display from the American, who hit 33 unforced errors on Court Philippe-Chatrier.
Elsewhere, Elena Rybakina, the 21st seed, claimed a comfortable 6-1 6-4 victory over Elena Vesnina.
Petra Kvitova's withdrawal through injury had handed Vesnina a second-round bye but the Russian was undone by Rybakina's dominant serve as she hit 12 aces and did not have to face a single break point.
Kazakhstan's Rybakina will next meet the winner of Friday afternoon's all-American meeting between 23-time Grand Slam champion Serena Williams and Danielle Collins.
Slovenia's Tamara Zidansek recovered from an opening-set whitewash to beat fellow non-seed Katerina Siniakova 0-6 7-6 (7-5) 6-2.
Sabalenka stunned as stuttering seeds suffer
Not since 2001 have so few top-10 seeds reached the women's third round at Roland Garros, although there are varying reasons behind the absence of so many top stars heading into the second week.
In addition to the high-profile withdrawals of Barty and reigning US and Australian Open champion Osaka, for injury and mental health reasons respectively, world number three Simona Halep pulled out pre-tournament with a calf problem.
On court, Sabalenka joined a casualty list featuring Karolina Pliskova, Bianca Andreescu and Belinda Bencic that, in addition to 11th seed Kvitova's injury, has opened the draw up considerably.
Sabalenka's exit means Williams, at seven, is the highest seed remaining in the bottom half of the draw, where an unseeded quarter-finalist is also guaranteed with Zidansek to meet either Romania's Sorana Cirstea or Russia's Daria Kasatkina in the last 16.
While that should aid the history-seeking Williams' bid to equal Margaret Court's record of 24 Grand Slam triumphs, the American is also arguably housed in the most difficult quarter of the draw.
Should she negotiate her way past Collins and Rybakina, the 39-year-old would then face Azarenka or Pavlyuchenkova in the quarter-finals.
Pavlyuchenkova, 29, has never been beyond the quarter-final of a Grand Slam but the Russian 31st seed came from 3-0 down to win the first set against Sabalenka.
The world number four - who has won five titles in Doha, Ostrava, Linz, Abu Dhabi and Madrid in the past 18 months but is yet to make an impact at a major - broke Pavlyuchenkova twice to take the second set.
But Sabalenka became increasingly erratic and frustrated after Pavlyuchenkova took an injury break for treatment to her thigh, failing to win a single game in the deciding set and hitting 39 unforced errors overall.
Defending champion Iga Swiatek, Elina Svitolina and American Sofia Kenin are the three top-10 seeds left in the top half of the draw, with all three playing their third-round matches on Saturday.