Roger Federer of Switzerland is on top of the log after Nadal lost in the Madrid Open quarter-finals. Photo: Rhona Wile/BackpagePix

PARIS – Rafael Nadal's surprise quarter-final exit at the Madrid Masters has seen the Spaniard replaced as world number one by Roger Federer in the latest ATP rankings published on Monday.

Federer returns to the top spot despite not having played since March.

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.

Subscribe to the IOL Sport Newsletter!

The ATP rankings as of May 14 are:

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)
29. Denis Shapovalov (CAN) 1.488 (+14)