Serena Williams gathering momentum at French Open

United States' Serena Williams celebrates after defeating compatriot Danielle Collins. Picture: AP Photo/Christophe Ena

Serena Williams laid down a marker in what is becoming a wide open women’s French Open with a straight-sets victory over fellow American Danielle Collins.

Williams arrived having won just one match on clay in the build-up and with five years having passed since she went beyond the fourth round at Roland Garros.