US Open champion Flavia Pennetta is up to eighth in the world rankings which are still headed by Serena Williams.
The 33-year-old defeated fellow Italian Roberta Vinci in Saturday's surprise final in New York for the first Grand Slam title of her career.
She promptly then announced that she had already decided to retire from competition at the end of the year.
Vinci, who upset favourite and calendar-year Grand Slam seeker Williams in the semi-finals, moves up 24 places to 19th.
The top four remain the same with Williams well clear of second-best Simona Halep, who lost to Pennetta in the semi-finals in New York.
The WTA world rankings at the conclusion of the US Open in New York:
1. Serena Williams (USA) 11,501 pts
2. Simona Halep (ROM) 6,780
3. Maria Sharapova (RUS) 5,795
4. Petra Kvitova (CZE) 5,295
5. Lucie Safarova (CZE) 3,570 (+1)
6. Caroline Wozniacki (DEN) 3,510 (-1)
7. Ana Ivanovic (SER) 3,440
8. Flavia Pennetta (ITA) 3,317 (+18)
9. Garbine Muguruza (ESP) 3,305
10. Karolina Pliskova (CZE) 3,215 (-2)
11. Angelique Kerber (GER) 3,150
12. Carla Suarez Navarro (ESP) 3,070 (-2)
13. Timea Bacsinszky (SUI) 2,836 (+1)
14. Agnieszka Radwanska (POL) 2,820 (+1)
15. Belinda Bencic (SUI) 2,735 (-3)
16. Elina Svitolina (UKR) 2,650 (+1)
17. Andrea Petkovic (GER) 2,450 (+1)
18. Madison Keys (USA) 2,445 (+1)
19. Roberta Vinci (ITA) 2,430 (+24)
20. Ekaterina Makarova (RUS) 2,380 (-7)
