Angelique Kerber suffered a shock first-round defeat on the opening day of the French Open.
The number-five seed went down to 18-year-old Anastasia Potapova in straight sets, 6-4, 6-2.
Kerber, the reigning Wimbledon champion, was aiming to complete her career slam at Roland Garros.
2016 winner Garbine Muguruza came from a set down to beat Taylor Townsend 5-7 6-2 6-2, while in the men's draw Stefanos Tsitsipas and Marin Cilic both progressed to the second round with straight sets wins over Maximilian Marterer and Thomas Fabbiano respectively.

Messi suffers muscle strain, Miami reschedule preseason finale
Man City and Villa close gap on Arsenal, Liverpool edge Sunderland
Djokovic withdraws from Doha with fatigue
Rutherford and Motie shine as West Indies sink England
Australia begin T20 World Cup with win over Ireland
