Spain's Rafael Nadal has replaced Roger Federer as the new world number one in the ATP rankings.
Twenty-seven-year-old Federer relinquishes his hold on the top spot after 237 weeks.
The Swiss player has struggled all season, while 22-year-old NADAL has played some of the best tennis of his career, winning eight titles including Roland Garros, Wimbledon and Olympic gold.
Nadal heads into next week's US Open seeking his third grand slam in a row after beating Federer in the finals in Paris and Wimbledon.