Karolina Pliskova became the sixth top 10 women's seed to exit the French Open on Thursday when she was knocked out by world number 227 Leolia Jeanjean.
Eighth-seeded Pliskova, last year's Wimbledon runner-up and a semi-finalist in Paris in 2017, lost 6-2, 6-2 to the 26-year-old Frenchwoman who cut her teeth as a leading college player in the United States.
Former number one Pliskova joins fellow top 10 seeds, defending champion Barbora Krejcikova, Maria Sakkari, Ons Jabeur, Anett Kontaveit and former winner Garbine Muguruza in failing to get through to the third round.
Jeanjean is the lowest-ranked woman to beat a top 10 player at Roland Garros in 34 years.
"I don't really realise what's going on. I find it just incredible," said Jeanjean, all smiles on the court just after his victory.
Considered a future star at 12, Jeanjean saw her career abruptly halted by injuries, including a triple dislocation of the knee.
She then left to study in the United States, only returning to top-level tennis at the end of 2020.
"I wanted to come back so as not to regret anything. I think I made the right choice," she said.
Pliskova has made the second week at Roland Garros just once in 11 visits.
World number three Paula Badosa overcame a scare to defeat 68th-ranked Kaja Juvan of Slovenia 7-5, 3-6, 6-2.
Badosa, a quarter-finalist in 2021, recovered from a break down in the decider to set up a meeting with 29th seed Veronika Kudermetova for a spot in the last 16.
Also going through was US 11th seed Jessica Pegula who needed eight match points to defeat Anhelina Kalinina of Ukraine 6-1, 5-7, 6-4.
- Swiatek eyes 30 in row -
Later Thursday, Daniil Medvedev, the second seed, faces Serbia's Laslo Djere who stunned the Russian on clay in their only meeting at Budapest five years ago.
That was courtesy of an injury retirement and Medvedev, gradually finding his feet on clay after making the last eight in Paris in 2021, should be favourite against the 56th-ranked Djere who has made the third round on two occasions.
However, Djere's two career titles have both come on clay in Rio in 2019 and Sardinia in 2020.
In his first round win on Tuesday, the 26-year-old Medvedev hammered 35 winners past Argentine qualifier Facundo Bagnis.
Fourth seed Stefanos Tsitsipas, the runner-up to Novak Djokovic last year, had to come back from two sets down to defeat Italy's Lorenzo Musetti in a first round tie which ended in the early hours of Wednesday.
"Leave your soul there and Valhalla will be waiting for you," Tsitsipas wrote on the courtside TV camera.
Tsitsipas faces Czech qualifier Zdenek Kolar, the world number 154 who won his first ever Grand Slam main draw match on Tuesday against French wildcard Lucas Pouille.
World number one Iga Swiatek can stretch her winning run to 30 matches by securing a place in the third round.
The Polish star is the overwhelming favourite to win a second Roland Garros title to add to her 2020 victory.
A win over Alison Riske of the United States will extend an undefeated streak which has guaranteed five successive titles.
In her opening round in Paris, Swiatek needed just 54 minutes to see off Ukrainian qualifier Lesia Tsurenko 6-2, 6-0.
She is unbeaten since February and has the longest winning streak on the WTA tour since Serena Williams won 34 matches in a row in 2013.
"I'm pretty sure that it can end, but I just want to keep going. I'm sure someday my streak will stop," she said.
Swiatek has defeated Riske on both occasions they have met in Rome and Madrid on clay last year.
© Agence France-Presse