Melbourne - Chung Hyeon will not be repeating last year's giant-killing heroics in the Australian Open after crashing out to Pierre-Hugues Herbert in the second round on Thursday.
The 24th seeded South Korean lost 6-2, 1-6, 6-2, 6-4 to the unseeded Frenchman on Melbourne Arena.
Twelve months ago the little-known Chung, who models his game on Novak Djokovic, was the toast of the town as he tore through a tough half of the draw before hitting the buffers against Roger Federer in the semi-finals.
Chung has struggled to build on his breakout performance where he famously beat fourth seed Alexander Zverev and Djokovic en route to retiring in the second set against Federer with massive, deep blisters on both feet.
The 22-year-old, who was the 2017 ATP NextGen Finals champion, is currently ranked 25 but will plummet when the new rankings are announced post-Melbourne and his points from last year drop off his record.
Herbert will face big-serving Milos Raonic in the thrid round, after the Canadian came through in four tiebreaks against the 2014 Australian Open champion Stan Wawrinka.
Results from Day 4 of the Australian Open on Thursday:
Kei Nishikori (JPN x8) bt Ivo Karlovic (CRO) 6-3, 7-6 (8/6), 5-7, 5-7, 7-6 (10/7)
Borna Coric (CRO x11) bt Marton Fucsovics (HUN) 6-4, 6-3, 6-4
Pablo Carreno-Busta (ESP x23) bt Ilya Ivashka (BLR) 6-2, 6-3, 7-6 (9/7)
Fabio Fognini (ITA x12) bt Leonardo Mayer (ARG) 7-6 (7/3), 6-3, 7-6 (7/5)
Joao Sousa (POR) bt Philipp Kohlschreiber (GER x32) 7-5, 4-6, 7-6 (7/4), 5-7, 6-4
Pierre-Hugues Herbert (FRA) bt Chung Hyeon (KOR x24) 6-2, 1-6, 6-2, 6-4
Milos Raonic (CAN x16) bt Stan Wawrinka (SUI) 6-7 (4/7), 7-6 (8/6), 7-6 (13/11), 7-6 (7/5)
Camila Giorgi (ITA x27) bt Iga Swiatek (POL) 6-2, 6-0
Wang Qiang (CHN x21) bt Aleksandra Krunic (SRB) 6-2, 6-3
Elina Svitolina (UKR x6) bt Viktoria Kuzmova (SVK) 6-4, 6-1
Karolina Pliskova (CZE x7) bt Madison Brengle (USA) 4-6, 6-1, 6-0
Anastasija Sevastova (LAT x13) bt Bianca Andreescu (CAN) 6-3, 3-6, 6-2
Elise Mertens (BEL x12) bt Margarita Gasparyan (RUS) 6-1, 7-5
Hsieh Su-wei (TPE x28) bt Laura Siegemund (GER) 6-3, 6-4
Madison Keys (USA x17) bt Anastasia Potapova (RUS) 6-3, 6-4
Timea Bacsinszky (SUI) bt Natalia Vikhlyantseva (RUS) 6-2, 7-5
Naomi Osaka (JPN x4) bt Tamara Zidansek (SLO) 6-2, 6-4
Zhang Shuai (CHN) bt Kristyna Pliskova (CZE) 6-3, 7-5