Spain's David Ferrer entered at number 10 while Andy Roddick of the United States dropped out in the only change to the leading 10.
Nadal, who is already assured of staying on top for the rest of the year, improved from 12 070 to 12 390 points.
Novak Djokovic of Serbia remains second unchanged on 7 145 points and former number one Roger Federer of Switzerland third, also unchanged on 6 735 points.
ATP top 10 as of October 11 (previous ranking in parenthesis):
1. (1) Rafael Nadal, Spain, 12 390 points
2. (2) Novak Djokovic, Serbia, 7 145
3. (3) Roger Federer, Switzerland, 6 735
4. (4) Andy Murray, Britain, 5 125
5. (5) Robin Soderling, Sweden, 4 825
6. (6) Nikolay Davydenko, Russia, 3 945
7. (7) Tomas Berdych, Czech Republic, 3 715
8. (8) Mikhail Youzhny, Russia, 3 345
9 (9) Fernando Verdasco, Spain, 3 330
10. (11) David Ferrer, Spain, 3 280