Melbourne: Chung Hyeon beat fourth-seeded Alexander Zverev 5-7, 7-6 (3), 2-6, 6-3, 6-0 in the third round at the Rod Laver Arena.
Chung is 2-0 against the Zverev family this week at Melbourne Park.
In the first round, Chung played Alexander's older brother Mischa. Chung advanced when Mischa retired with a viral illness while trailing 6-2, 4-1.
Chung becomes the first South Korean man ever to reach the round of 16 at the Australian Open and will next face either Novak Djokovic or Albert Ramos-Vinolas.
The 20-year-old Alexander Zverev won five tournaments last year and has been tipped as a future Grand Slam champion.
Naomi Osaka clinched her match with an ace, beating local hope Ashleigh Barty 6-4, 6-2 to advance to the fourth round at Melbourne Park.
The Japanese 20-year-old's win finally marked some success in the third round at a major — she was previously 0 for 5.
The match was originally scheduled for Rod Laver Arena but was moved to Margaret Court Arena due to a backlog of long matches at the larger venue.
Osaka will next play top-seeded Simona Halep.
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Updated Date: Jan 20, 2018 13:53:40 IST