Switzerland’s Jil Teichmann, ranked 170th in the world, stunned Czech 10th seed Karolina Muchova 6-1 7-5 in the third round of the French Open.
Teichmann will take on last year’s semi-finalist Russian eight seed Mirra Andreeva in the last 16. Andreeva beat Czech Marie Bouzkova 6-4 6-2 to reach the fourth round.
Elsewhere, Romanian 18th seed Sorana Cirstea thrashed Argentina’s Solana Sierra 6-0 6-0 as the 36-year-old became the oldest player in the Open Era to win by double bagel in a Grand Slam main draw.
Cirstea will next face China’s Wang Xiyu.
Four-times champion Iga Swiatek eased into the fourth round with a 6-4 6-4 victory over Magda Linette in an all-Polish clash.
In the men’s competition, former quarter-finalist Andrey Rublev was tested by Portugal’s Nuno Borges, but the Russian 11th seed stayed cool in the tiebreaks to win the third round match 7-5 7-6(2) 7-6(2).