Rafa Nadal is looking to win a spot in this week's quarter finals.
Rafa Nadal is among those in last 16 action at the US Open later.
The number two seed - who is a four-time champion at Flushing Meadows - plays Frances Tiafoe.
Elsewhere in the men's singles, Cameron Norrie takes on Andrey Rublev from 4pm Irish time.
Overnight, defending champion Daniil Medvedev was knocked out by Nick Kyrgios.
In the women's singles, top seed Iga Swiatek meets Jule Niemeier of Germany for a place in the quarter finals.
There's also a meeting of two former finalists when Victoria Azarenka goes up against Karolina Pliskova.
The other match this evening sees former Wimbledon champion Petra Kvitova take on Jessica Pegula.
Sixth seed Aryna Sabalenka meets Danielle Collins in the early hours of tomorrow morning.