Aleksandar Vukic has led the Australian charge into the third round of the ATP Tour event in Winston-Salem, North Carolina.
In promising form ahead of the US Open which gets underway next week, the world No.94 defeated fourth seed and 2022 champion Adrian Mannarino 7-6 (7-5) 2-6 6-1 in a tick over two hours on Monday.
Joining the 28-year-old in the last 32 is fellow Sydneysider Rinky Hijikata after the 14th seed overcame another Frenchman, Arthur Cazaux, 4-6 6-3 7-6 (7-4).
In his first meeting with 36-year-old Mannarino, Vukic fired down 15 aces and hit 31 winners as he overcame the 42nd-ranked left-hander.
He will next face Kazakh Alexander Shevchenko or Pablo Carrena Busta of Spain for a place in the last 16, while world No.65 Hijikata will take on either top-seeded Argentine Sebastien Baez or Borna Coric of Croatia.
Meanwhile, Chris O'Connell won his opening-round clash against American qualifier Strong Kirchheimer 7-5 6-4, but fellow Aussie Tristan Schoolkate suffered a 3-6 6-2 6-3 loss to local Learner Tien.
There were also wins for Belgian veteran David Goffin, lucky loser Zachary Svajda of the US and China's NextGen star Shang Juncheng.
