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.

Dimitrov marks return from pectoral injury with win in Paris
Real Madrid captain Carvajal faces knee surgery setback
Simeone and Baena strike as Atletico beat Betis to extend unbeaten run
Juventus sack coach Tudor after eight-match winless run
India's Iyer taken to hospital after fielding injury
