Barbora Krejcikova became the first player since Mary Pierce in 2000 to win the singles and doubles titles at the French Open on Sunday.
Krejcikova teamed with fellow Czech Katerina Siniakova to defeat Bethanie Mattek-Sands and Iga Swiatek 6-4, 6-2 for their third Slam title together.
"It's an extraordinary achievement to win in singles and doubles," said Swiatek who was singles champion in 2020.
Krejcikova on Saturday had become the first Czech woman since Hana Mandlikova in 1981 to lift the singles title with a three-set win over Anastasia Pavlyuchenkova.
Krejcikova and Siniakova also won the 2018 doubles title in Paris and backed it up the same year at Wimbledon.
"It was really difficult. Like yesterday there were so many emotions and everything. I didn't really sleep well," said Krejcikova.
"I woke up in the morning and I felt really tired. I can actually say that out loud right now, I'm having some pains in my leg."