Paris - Roger Federer has closed the gap on Rafael Nadal at the top of the latest ATP Tour's world rankings released on Monday following his victory over the Spaniard at the Shanghai Masters.
Nadal remains well clear of Federer, but the Swiss maintains a chance of finishing the year as world number one after shaving more than 400 points off his lead.
Federer claimed a surprisingly one-sided 6-4, 6-3 victory over the world number one on Sunday to secure a 94th career title, drawing him level with the great Ivan Lendl.
Only Jimmy Connors (109) has won more trophies.
Meanwhile, Marin Cilic reaches his best ever ranking of fourth after his run to the semi-finals in Shanghai.
Novak Djokovic and Stan Wawrinka, whose seasons are both over due to injury, each slip a place but Juan Martin Del Potro continued his climb up the rankings.
The Argentine rises four places to 19th, appearing in the top 20 for the first time in three years.
For the moment only Nadal, Federer, Alexander Zverev and Dominic Thiem have confirmed their places at the end-of-season Masters in London next month.
Top 20 in the latest ATP Tour rankings:
1. Rafael Nadal (ESP) 10,465 points
2. Roger Federer (SUI) 8,505
3. Andy Murray (GBR) 5,290
4. Marin Cilic (CRO) 4,505
5. Alexander Zverev (GER) 4,400
6. Dominic Thiem (AUT) 3,935
7. Novak Djokovic (SRB) 3,765
8. Grigor Dimitrov (BUL) 3,590
9. Stan Wawrinka (SUI) 3,450
10. David Goffin (BEL) 2,885
11. Pablo Carreno (ESP) 2,855
12. Milos Raonic (CAN) 2,600
13. John Isner (USA) 2,550
14. Sam Querrey (USA) 2,525
15. Kei Nishikori (JPN) 2,475
16. Kevin Anderson (RSA) 2,470
17. Jo-Wilfried Tsonga (FRA) 2,285
18. Tomas Berdych (CZE) 2,230
19. Juan Martin Del Potro (ARG) 2,225
20. Nick Kyrgios (AUS) 2,010