Defending champion Iga Swiatek celebrated her 20th birthday with victory over Slovenia’s Kaja Juvan in the French Open first round.
The Polish eighth seed beat her best friend on the tour 6-0 7-5.
“She didn’t give me any birthday gifts so I’m really happy I could win those important points,” Swiatek said in her on-court interview.
Swiatek, on a seven-match unbeaten run since winning in Rome, will face Sweden’s Rebecca Peterson next.
There was, however, disappointment for Dutch 16th seed Kiki Bertens, who lost 6-1 3-6 6-4 to Slovenia’s Polona Hercog.
British number one Johanna Konta, seeded 19th, plays Romanian Sorana Cirstea later in the day at Roland Garros, while compatriot Heather Watson is playing Kazakhstan’s Zarina Diyas.
Among the other players who are opening their campaigns on Monday are American 23-time Grand Slam champion Serena Williams, who faces Romanian Irina-Camelia Begu in the French Open’s first night session (20:00 BST).