Alex de Minaur has defeated Hubert Hurkacz in the first round of the ATP Tour's Atlanta Open.
The 19-year-old - the youngest player in the field - fought back from dropping the first set to win two tiebreakers to prevail 1-6 7-6 (7-0) 7-6 (7-5).
"It wasn't the prettiest of wins but it's a very important win for me," De Minaur told the official ATP Tour website.
"I managed to dig deep, stay tough and beat a quality opponent."
The Australian had his serve broken four times by his Polish opponent and won three less points in total but was too good in the crunch moments.
"I just tried to stay positive throughout the whole match, tried to dig deep," De Minaur said.
World No.68 De Minaur progressed to a second-round meeting with American top seed John Isner.
Slovakia's Lukas Lacko was too good for Indian Prajnesh Gunneswaran winning 6-2 6-2.
Croatian veteran Ivo Karlovic leads Donald Young 6-2 5-5 with the match suspended due to rain.
Of the other Australians; James Duckworth's scheduled Monday first-round encounter with eighth-seeded American Ryan Harrison has been delayed due to rain while qualifiers Thanasi Kokkinakis and Alex Bolt are in action on Tuesday.
Nick Kyrgios, the second seed, and fourth-seeded Matt Ebden have first-round byes.
