Emma Raducanu reached the Australian Open third round for the first time in her career with a dogged victory over American opponent Amanda Anisimova.
The 22-year-old Briton won 6-3 7-5 to set up a meeting with Polish second seed Iga Swiatek next.
Raducanu's preparations for the opening Grand Slam of the season were hampered by a back injury and she needed treatment twice during the second-round match.
But the world number 61 managed to find a way to beat Anisimova - a friend who is ranked 35th - in a tussle where there were 13 breaks of serve.