Paris - Roger Federer has dropped out of the top three places in the ATP world rankings for the first time since just before he won the first of his 16 Grand Slam titles at Wimbledon in July, 2003.
Federer falls to fourth due to Andy Murray's win Sunday in the Shanghai Masters, his third straight ATP title triumph in Asia during the last month.
Murray has few points to defend before the end of the season and with Federer sidelined with an injury, the Scot is well-placed to end the season as world number three for the first time.
Serbia's Novak Djokovic, who has won the Australian and US Opens as well as Wimbledon this year remains comfortably ahead despite taking time off to rest a back injury. French Open winner Rafael Nadal of Spain stays in second.
South Africa's top ranked player, Kevin Anderson dropped one place to fall outside of the top 30 after his first round exit in Shanghai.
ATP world top 20:
1. Novak Djokovic (SRB) 13860 pts
2. Rafael Nadal (ESP) 10375
3. Andy Murray (GBR) 7825 (+1)
4. Roger Federer (GBR) 7780 (-1)
5. David Ferrer (ESP) 4710
6. Robin Soderling (SWE) 3500
7. Tomas Berdych (CZE) 3230
8. Mardy Fish (USA) 2965 (+1)
9. Jo-Wilfried Tsonga (FRA) 2880 (-1)
10. Gal Monfils (FRA) 2525
11. Nicolas Almagro (ESP) 2380
12. Gilles Simon (FRA) 2335
13. Andy Roddick (USA) 2120 (+2)
14. Janko Tipsarevic (SRB) 2040 (-1)
15. Juan Martn Del Potro (ARG) 2030 (-1)
16. Viktor Troicki (SRB) 1920
17. Alexandr Dolgopolov Jr. (UKR) 1880 (+1)
18. Richard Gasquet (FRA) 1810 (-1)
19. Stanislas Wawrinka (SUI) 1765
20. Florian Mayer (GER) 1735 (+3)
31. Kevin Anderson (RSA) 1220 (-1)