Federer has returned to the top spot despite not having played since March, replacing Nadal after his surprise quarter-final exit at the Madrid Masters.
Former world No. 1 Novak Djokovic slipped six places to 18th after his second round defeat in Madrid, his lowest ranking since October 2006.
Madrid winner Alexander Zverev remains in third, but the man he beat in Sunday’s final, Dominic Thiem, dropped a place to eighth despite knocking out Nadal on his way to facing Zverev.
Thiem saw off Kevin Anderson in the semi-finals and it is the South African who inherits his seventh spot, the 31-year-old’s highest ever ranking.
The highest mover in the men’s charts is Madrid semi-finalist Denis Shapovalov with the Russian teenager jumping 14 rungs to a best ever 29th.
ATP rankings as of May 14
1. Roger Federer (SUI) 8,670 pts (+1)
2. Rafael Nadal (ESP) 7,950 (-1)
3. Alexander Zverev (GER) 6,015
4. Grigor Dimitrov (BUL) 4,870
5. Marin Cilic (CRO) 4,770
6. Juan Martin Del Potro (ARG) 4,540
7. Kevin Anderson (RSA) 3,660 (+1)
8. Dominic Thiem (AUT) 3,545 (-1)
9. John Isner (USA) 3,305
10. David Goffin (BEL) 2,930
11. Pablo Carreno (ESP) 2,280
12. Sam Querrey (USA) 2,220 (+1)
13. Roberto Bautista (ESP) 2,210 (+1)
14. Jack Sock (USA) 2,155 (+1)
15. Diego Schwartzman (ARG) 2,130 (+1)
16. Lucas Pouille (FRA) 1,995 (+2)
17. Tomas Berdych (CZE) 1,980
18. Novak Djokovic (SRB) 1,905 (-6)
19. Kyle Edmund (ENG) 1,905 (+3)
20. Hyeon Chung (KOR) 1,807 (+1)
Selected
29. Denis Shapovalov (CAN) 1.488 (+14)
