Paris - Japan's Naomi Osaka remained atop of WTA rankings released on Monday, ahead of Czech Petra Kvitova and Romanian Simona Halep.

The largely unchanged top 20 saw Belgian Elise Mertens drop two places to 20th after being knocked out of the first round of the Madrid Open on Sunday by Slovakia's Anna Karolina Schmiedlova, 103rd in the world.

Top 20 in the latest WTA Tour rankings:

1. Naomi Osaka (JPN) 6 151

2. Petra Kvitova (CZE) 5 835

3. Simona Halep (ROM) 5 682

4. Angelique Kerber (GER) 5 220

5. Karolina Pliskova (CZE) 5 111

6. Elina Svitolina (UKR) 4 921

7. Kiki Bertens (NED) 4 765

8. Sloane Stephens (USA) 4 386

9. Ashleigh Barty (AUS) 4 275

10. Aryna Sabalenka (BLR) 3 520

11. Serena Williams (USA) 3 461

12. Caroline Wozniacki (DEN) 3 362

13. Anastasija Sevastova (LAT) 3 185

14. Madison Keys (USA) 3 010

15. Anett Kontaveit (EST) 2 965

16. Qiang Wang (CHN) 2 815

17. Julia Goerges (GER) 2 630

18. Belinda Bencic (SUI) 2 540

19. Garbine Muguruza (ESP) 2525 (+1)

20. Elise Mertens (BEL) 2360 (-2)