AUSTRALIA'S last man standing, John Millman, has continued on his winning ways in New York by reaching the third round of the US Open.

Daria Gavrilova, however, suffered heartbreak when she lost the longest ever women's match at Flushing Meadows - a three-hour, 33-minute epic.

It left Ashleigh Barty as the lone Aussie woman left. She will play early on Saturday.

After upsetting countryman Nick Kyrgios, Queenslander Millman followed up with a 6-1 7-6 (7-1) 6-1 victory over Tunisian Malek Jaziri to book his place in the last 32.

Ranked No.235 in the world, Millman will attempt to become the lowest-ranked player since No.730 Jay Burger in 1985 to make the last 16 with a battle against German Philipp Kohlschreiber to come (1am Sunday).

Plagued by injuries - the latest a groin complaint - the 28-year-old felt good physically, despite having to back up less 24 hours after dispatching Kyrgios.

"I was probably slightly apprehensive yesterday as to how my body would pull up," he said.

"I am extremely happy with the level I am at and how I am hitting the ball.

"I am starting to play the big points better, which is really important when you are coming back from injury.

"Because when you have lacked that match experience, it is really difficult to be super clinical."

Millman reached the third rounds at the Australian Open and Wimbledon last year - his best efforts at a grand slam.

Gavrilova saved four match points before finally being defeated 7-6 (8-6) 4-6 7-6 (7-5)by American Shelby Rogers in their second-round clash.

The Australian led 4-2 in the deciding set and then missed two break-point chances to go up 5-2, with Rogers claiming four games in a row to advance.