Nadal on top of the world

Federer, 27, relinquishes his hold on the top spot after 237 weeks.

The Swiss player has struggled all season, while Nadal, 22, has played some of the best tennis of his career, winning eight titles including Roland Garros, Wimbledon and the Olympic gold.

Asked about his feelings on becoming number one, the Mallorcan left-hander, said: "I'm very happy to be number one. But the feeling doesn't change too much because the last years I did very well, too.

"I was very happy being the number two. So finally I'm number one. For sure there's satisfaction, but at the same time ... I don't know. I don't have time to celebrate. I play New York in one week."

He is seeking his third Grand Slam in a row after beating Federer in the finals in Paris and Wimbledon.

Olympic finalist Fernando Gonzalez of Chile moves up four places to 11th, while Argentine Juan Martin Del Potro, winner of his fourth consecutive title in Washington Sunday after Kitzbuhel, Stuttgart and Los Angeles, moves to 17th.

1. Rafael Nadal (ESP) 6700 (+1)

2. Roger Federer (SUI) 5930 (-1)

3. Novak Djokovic (SRB) 5105

4. David Ferrer (ESP) 2865

5. Nikolay Davydenko (RUS) 2700

6. Andy Murray (GBR) 2415

7. David Nalbandian (ARG) 1975 (+1)

8. Andy Roddick (USA) 1845 (+1)

9. James Blake (USA) 1825 (-2)

10. Stanislas Wawrinka (SUI) 1695

11. Fernando Gonzalez (CHI) 1615 (+4)

12. Richard Gasquet (FRA) 1595 (-1)

13. Fernando Verdasco (ESP) 1425

14. Ivo Karlovic (CRO) 1405 (+2)

15. Tommy Robredo (ESP) 1360 (25)

16. Gilles Simon (FRA) 1350 (-2)

17. Juan Martin Del Potro (ARG) 1345 (+2)

18. Nicolas Almagro (ESP) 1305 (-6)

19. Jo-Wilfried Tsonga (FRA) 1265 (-1)

20. Nicolas Kiefer (GER) 1225 (+1)