The 23-year-old — who won her fifth title in six years later this month at the French Open — won the quarterfinals in at least eight previous games, but has not won the trophy this season.
Japan's Naomi Osaka continued to beat Swiss Lucky Loser Viktorija Golubic 2-6 7-5 6-1 on Clay.
The 27-year-old has traditionally struggled with clay and failed to surpass the third round of the French Open, but has now won seven consecutive games on the surface.
Her victory at De Saint-Malo last week was her first clay field champion – any ostensibly first WTA title since becoming a mother in July 2023.
Osaka was originally scheduled to be the ninth seed Paula Badosa, but the Spaniard was replaced by golubic due to injury.
Next, the four-time Grand Slam champion will play Brazil's 18th seed Beatriz Haddad Maia or Marie Bouzkova of the Czech Republic.
The French Open begins on May 25 at Roland Garros.
