Russian-born world number 12 Daria Kasatkina won her first match representing Australia in the second round of the Charleston Open on Wednesday.
Fifth seed Kasatkina, who won her first tour-level title at the WTA 500 event in 2017, needed just 61 minutes to dispatch home hopeful Lauren Davis 6-1, 6-1 and book a third round match against another American, Sofia Kenin.
The 27-year-old announced last Friday that her application for permanent residency had been accepted by the Australian government.
Kasatkina had previously been playing on the tour as a neutral athlete after Russian and Belarusian players were banned from competing under their own flags following Moscow's invasion of Ukraine in 2022.
Top seed Jessica Pegula also advanced into the third round on Wednesday, holding off a second set comeback attempt from Belarus' Iryna Shymanovich.
The 2024 U.S. Open finalist bageled Shymanovich in the first set before seeing her serve broken twice in the second.
Pegula, held firm, however to prevail 6-0, 6-3 and set up a third round tie against Australia's Alija Tomljanovic.
Elsewhere, fourth seed Emma Navarro defeated her American compatriot Hailey Baptiste 6-4, 6-3.