Madison Keys has reached the Australian Open third round after coming from behind to defeat 29th seed Casey Dellacqua.
The 19-year-old, who is regarded as one of the United States' top talents, ran out a 2-6 6-1 6-1 winner over the Australian.
It was Dellacqua who made all of the early running on the Margaret Court Arena as Keys made a catalogue of errors in dropping the opening set in 27 minutes.
However, Keys, who also beat Dellacqua on her Melbourne debut in 2013, struck 16 winners during a dominant second set to ensure that the contest went the distance.
Dellacqua was struggling to make any kind of impact as Keys's power continued to control their baseline exchanges, and the youngster wasted little time in securing victory in one hour 27 minutes.
Keys will now take on fourth seed Petra Kvitova in the last 32 on Saturday.