New York, United States, 29 August 2019 | Darren Walton (AAP)

Nick Kyrgios is among five Australians to venture to the second round of the US Open men’s singles this year, all of whom feature in action on Day 4 at Flushing Meadows.

With his straight-sets victory over Steve Johnson on Tuesday night in New York, Kyrgios was the fourth Australian man to win his opening-round match.

AUSSIES IN ACTION: US Open Day 4

Kyrgios, Thanasi Kokkinakis, Jordan Thompson and Alexei Popyrin joined Alex de Minaur — who had won his opening match a day earlier —  in the last 64.

“When I see these results, it makes me want to push harder but it makes me excited that Australia right now, the depth’s pretty scary,” Kyrgios said, when asked about the success of the Aussies on Tuesday.

The 28th seed and Australia’s highest-ranked male player was particularly pleased for Thanasi Kokkinakis, whose win over Ilya Ivashka was his first at a slam since the 2015 French Open.

RELATED: Kokkinakis back on Grand Slam big stage at US Open

“Obviously Thanasi’s massive,” Kyrgios said.

“It’s just so good to see someone I grew up with, who’s been dealt unbelievably unlucky injuries – he’s had to deal with so many rough patches in his career – to see him back.

“As soon as I saw the result, I was so happy for him. I sent him a video and it was just so good to see him pull up well. I actually saw him after the match and he looked like his body was holding up and he just looked happy.

“And obviously Thommo (Jordan Thompson) to beat (Joao) Sousa in straight sets, that’s really, really good.

“And (Alexei) Popyrin, he’s going to have a great career. He plays big, he likes to keep things on his terms – big serve and he hits the ball big. So I wasn’t surprised when I saw him beat (Federico) Delbonis on these type of courts.”