Defending champion Daniil Medvedev is out of the US Open.
The Russian suffered defeat in four sets to Australia's Nick Kyrgios in their last 16 clash overnight.
Medvedev is also set to lose his place as the world's number one player.
In the women's draw, fifth seed Ons Jabeur is safely through after a straight sets win over Veronika Kudermetova.
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Rafa Nadal faces a tough challenge as he aims to book his spot in the quarter finals today.
The Spaniard goes up against the 22nd seed, Frances Tiafoe.
Elsewhere, Britain's Cameron Norrie faces Andrey Rublev of Russia and Marin Cilic takes on Carlos Alcaraz.
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In the women's singles, top seed Iga Swiatek takes on Jule Niemeier of Germany for a place in the quarter finals.
2020 beaten finalist Victoria Azarenka battles 2016 runner up Karolina Pliskova in the last 16 this evening.
The other matchups today sees former Wimbledon champion Petra Kvitova take on Jessica Pegula, while sixth seed Aryna Sabalenka meets Danielle Collins.
