NEW YORK, NY, USA -- Defending champion Naomi Osaka and reigning runner-up Serena Williams both claimed Top 8 positions as the USTA announced the women's singles seedings for the US Open on Wednesday.

World No.1 Osaka heads the field with the No.1 seeding, as the Japanese superstar heads into New York City with aims of defending her title. Osaka defeated Williams to capture her first-ever Grand Slam title last season, and followed up by winning a second successive Grand Slam title at the Australian Open in January. Osaka is 14-0 in the last two hardcourt Grand Slam events.

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The other two current Grand Slam champions are also seeded in the Top 4. Australia's Ashleigh Barty, who won her first-ever Grand Slam title on the clay courts of Roland Garros, is seeded No.2, while Romania's Simona Halep, who earned her second Grand Slam title on the grass of Wimbledon, is seeded No.4.

Former World No.1 Karolina Pliskova of the Czech Republic, who reached the US Open final in 2016, rounds out the Top 4 seeds, at No.3.

Williams is seeded No.8, having reached the finals at her last two events, Wimbledon and the Rogers Cup in Toronto. The American legend goes into New York City seeking the 24th Grand Slam title of her career.

No.5 seed Elina Svitolina of Ukraine, No.6 seed and two-time Wimbledon champion Petra Kvitova of the Czech Republic, and No.7 seed Kiki Bertens of the Netherlands complete the Top 8 seeds, as the seedings adhered to the most recent WTA Rankings from Monday, August 19th.

Belarusian Aryna Sabalenka is seeded No.9, while Americans Madison Keys and Sloane Stephens are seeded No.10 and No.11 respectively. Stephens defeated Keys in the 2017 US Open final.

2016 US Open champion Angelique Kerber of Germany is seeded No.14, while two-time US Open finalist Caroline Wozniacki of Denmark is seeded No.19.

The full list of seeds for the 2019 US Open is as follows:

1. Naomi Osaka, Japan
2. Ashleigh Barty, Australia
3. Karolina Pliskova, Czech Republic
4. Simona Halep, Romania
5. Elina Svitolina, Ukraine
6. Petra Kvitova, Czech Republic
7. Kiki Bertens, Netherlands
8. Serena Williams, United States

9. Aryna Sabalenka, Belarus
10. Madison Keys, United States
11. Sloane Stephens, United States
12. Anastasija Sevastova, Latvia
13. Belinda Bencic, Switzerland
14. Angelique Kerber, Germany
15. Bianca Andreescu, Canada
16. Johanna Konta, Great Britain

17. Marketa Vondrousova, Czech Republic
18. Qiang Wang, China
19. Caroline Wozniacki, Denmark
20. Sofia Kenin, United States
21. Anett Kontaveit, Estonia
22. Petra Martic, Croatia
23. Donna Vekic, Croatia
24. Garbiñe Muguruza, Spain

25. Elise Mertens, Belgium
26. Julia Goerges, Germany
27. Caroline Garcia, France
28. Carla Suárez Navarro, Spain
29. Su-Wei Hsieh, Chinese Taipei
30. Maria Sakkari, Greece
31. Barbora Strycova, Czech Republic
32. Dayana Yastremska, Ukraine