(Photo credit: Phil Didion/The Enquirer / USA TODAY NETWORK)

No. 2 seed Coco Gauff overcame a slow start to beat Russia's Liudmila Samsonova 7-5, 6-1 in her opening match of the Porsche Tennis Grand Prix Thursday to advance into the quarterfinals in Stuttgart, Germany.

Gauff dropped the first three games of the match but won the next four to take command and then rolled to an easy second-set victory. She finished with seven aces and five double faults. Next up will be No. 7 seed Karolina Muchova of the Czech Republic, who rallied for a 1-6, 6-3, 6-0 defeat of Belgium's Elise Mertens. Gauff, looking for her first semifinal appearance in Stuttgart, holds a 6-0 record in the head-to-head series.

No. 1 Elena Rybakina of Kazakhstan won her opener 6-3, 6-4 over Diana Shnaider of Russia in 73 minutes, and No. 6 Mirra Andreeva of Russia swept Alycia Parks 7-6 (3), 6-3. No. 8 Ekaterina Alexandrova was the lone seeded competitor who lost Thursday, falling 6-1, 6-1 in 58 minutes to Czech Linda Noskova.

In the final match of the day, Canada's Leylah Fernandez survived a three-hour marathon against Zeynep Sonmez of Turkey, coming away with a 6-7 (2), 6-1, 7-6 (5) victory to set up a quarterfinal versus Rybakina.

Rouen Metropolitan Open

Belarus' Iryna Shymanovich knocked off No. 4 Hailey Baptiste for a 6-3, 5-7, 6-3 victory for her first career top-50 win in Rouen, France.

While Baptiste held a 7-0 advantage in aces, Shymanovich had twice as many breaks (4-2) to earn her first career tour-level quarterfinal appearance at 28 years old. She'll face unseeded German Tatjana Maria, who swept Czech Dominika Salkova 6-3, 6-2 for a spot in the semifinals.

No. 2 Sorana Cirstea of Romania advanced to the quarterfinals via first-round retirement by China's Xinyu Wang, but No. 7 Elisabetta Cocciaretto was not as fortunate, falling 7-6 (5), 4-6, 6-4 to Veronika Podrez of Ukraine. Hungary's Anna Bondar beat Ukraine's Oleksandra Oliynykova 6-0, 4-6, 6-0 in the opening match of the day.

--Field Level Media