Jo-Wilfried Tsonga of France in action against Ernests Gulbis of Latviat during their men’s single third round match at the French Open tennis tournament at Roland Garros in Paris, France, 28 May 2016. EPA/IAN LANGSDON

Kristina Mladenovic of France in action against Serena Williams of the USA during their women’s single third round match at the French Open tennis tournament at Roland Garros in Paris, France, 28 May 2016. EPA/ETIENNE LAURENT

Alexander Zverev of Germany in action against Stephan Robert of France during their men’s single second round match at the French Open tennis tournament at Roland Garros in Paris, France, 26 May 2016.??? EPA/ETIENNE LAURENT

Dominic Thiem of Austria in action against Guillermo Garcia-Lopez of Spainduring their men’s single second round match at the French Open tennis tournament at Roland Garros in Paris, France, 26 May 2016. EPA/ROBERT GHEMENT

Simona Halep of Romania in action against Naomi Osaka of Japan during their women’s single third round match at the French Open tennis tournament at Roland Garros in Paris, France, 27 May 2016. EPA/ROBERT GHEMENT