An ailing Novak Djokovic crashed out of the Australian Open in the fourth round as up and comer Hyeon Chung clinically took advantage of the six-time champion's elbow injury to win 7-6 (7-4) 7-5 7-6 (7-3).
The Serbian, who had also struggled with his hip in the third round, was on the back foot from the off and failed to claw back the first set before suffering further at the start of the second.
Djokovic's fighting spirit never wavered, but he could not shake off NextGen champion Chung, who was unrelenting en route to claiming the biggest scalp of his career.
Chung – the first Korean male or female to reach a grand slam quarter-final – had said prior to the match that he would "just be happy to share the court with Novak", but he was far from starstruck and an outstanding performance made him a deserved winner - albeit Djokovic, who missed six months before returning to play in Melbourne, was undoubtedly hindered by his injury.
The 21-year-old will now face another shock quarter-finalist in Tennys Sandgren on Wednesday.
Welcome to the big time Hyeon #Chung!— #AusOpen (@AustralianOpen) January 22, 2018
Our six-time champion Novak #Djokovic bows out of the #AusOpen d by the world No.58 in straight sets 7-6(4) 7-5 7-6(3) after 3hrs 21mins. pic.twitter.com/lETvt3JPJC
A series of unforced errors, including numerous double faults, allowed Chung to break Djokovic's serve twice and move 4-0 up in the first set, before the former world number one came roaring back.
Three successive games piled the pressure on Chung and errors crept into the youngster's play as he served for the set, but he battled through to the tie-break and recovered his momentum to take the set.
It was clear that Djokovic, wearing a protective sleeve on his right arm, was struggling with his elbow as he repeatedly failed to hold serve and he received treatment before the second set.
Chung held his nerve in a gruelling first game and broke the 14th seed en route to building a 3-0 lead.
As in the first set, Djokovic's fighting spirit came to the fore as he drew level, but Chung again showed great resolve and he moved two sets ahead when a stunning rally ended with the groaning 30-year-old finding the net.
A topsy-turvy third set followed, bringing the crowd to its feet as four of the first five service games were broken to leave the pair neck and neck.
Both players missed big opportunities to then take control of proceedings and a number of poorly telegraphed drop shots from the world number 58 ensured Djokovic remained in the match.
But Chung kicked off the tie-break with two superb points and, although again there was a strong response, he continued to confound Djokovic with some astounding returns to seal a huge win.
Chung bt Djokovic  7-6 (7-4) 7-5 7-6 (7-3)
Chung – 47/37
Djokovic – 36/57
Chung – 1/2
Djokovic – 2/9
BREAK POINTS WON
Chung – 6/10
Djokovic – 5/19
FIRST SERVE PERCENTAGE
Chung – 67
Djokovic – 62
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Chung – 65/47
Djokovic – 65/39
Chung – 138
Djokovic – 128
|Messi: I´d give up Barca title for World Cup glory|
|LeBron reaching eight straight Finals is ridiculous and unbelievable – Stevens|
|Indians top Astros in 14 innings as Cole-Bauer duel turns into marathon|
|I´m squeezing this orange until there´s no juice left – LeBron|
|LeBron James leads Cavs past Celtics and into NBA Finals|
|Kyle Busch dominates to win Coca-Cola 600|
|Henderson still confident of Liverpool success|
|Sporting Kansas City 0 Columbus Crew 0: 10-man visitors battle to MLS draw|
|Inglis to captain new-look Maroons, Boyd and Scott axed for Origin I|
|Neymar labels Real Madrid links ´nonsense´|
|Koepka ready to turn seconds into wins|
|Rose ´really proud´ of Fort Worth Invitational win|
|Paul a ´game-time decision´ for series decider, says Rockets coach D´Antoni|
|Egypt president wishes Salah speedy recovery|
|Bonucci: Balotelli has matured|
|Ranieri backs Sarri to succeed at Chelsea|
|Konta admits to doubts after another early Roland Garros exit|
|Warriors´ Iguodala, Looney listed as questionable for game seven|
|Zverev batters Berankis, Goffin back from the brink in Paris|
|Rose cruises to victory at Colonial|
|Neymar: I´m not at 100 per cent yet|
|Toulouse confirm Ligue 1 survival with win over Ajaccio|
|I know what I´ve achieved - Bale not worried about plaudits as he looks to the future|
|Ostapenko ´angry´ after Roland Garros exit, Venus Williams falls at first hurdle|
|Barcelona B relegated to Spain´s third tier|
|Rayo Vallecano win promotion to LaLiga|
|Tarkowski leaves England camp for hernia surgery|
|Ramos ´quite clever´ but Salah injury not to blame for final defeat, insists Robertson|
|WATCH: Ricciardo takes wide receiver role on yacht for Tom Brady pass|
|Until next year – Ronaldo drops new future hint as Real Madrid celebrate with fans|
|Froome stunned by Giro triumph|
|The Triple Crown: Froome´s Grand Tour glory in numbers|
|Hannover sign Wimmer on season-long loan|
|Inter powerless to stop Icardi exit, admits Spalletti|
|Ashton makes England statement with Barbarians hat-trick|
|Watson masterclass seals third IPL title for Super Kings|
|Kozlova ends Ostapenko´s Roland Garros reign on day one|
|Imperious Zverev breezes into second round|
|Froome wins Giro d´Italia to complete Triple Crown|
|Stricken Salah confident over World Cup hopes|
|Verstappen highlights change in approach amid Rosberg criticism|
|Strinic claims three-year deal at Milan|
|Napoli captain Hamsik considering China offer|
|Chinese outsider Wang shocks Venus Williams in Paris|
|Redemption two years in the making - Ricciardo revels in Monaco glory|
|Flawless Molinari holds off McIlroy at Wentworth|
|Karius ´infinitely sorry´ but thanks Liverpool fans for support|
|Root and Bayliss dismiss ´outrageous´ fixing allegations|
|Giggs: Bale the best Welsh player I´ve seen|
|Ricciardo ends Monaco hoodoo despite mechanical issue|
|Lyon star Fekir denies being close to Liverpool switch|
|Pogba: I learned a lot from Abou Diaby|
|Where next for Real Madrid stars Ronaldo and Bale?|
|Shingler and Hewitt out of Wales tour|
|Kyrgios pulls out of French Open|
|Khan wants to bow out by winning blockbuster Brook fight|
|Is winter coming? Game of Thrones stars descend on Monaco|
|Root urges England´s batsmen to ´find a way´|
|Lovren, Van Dijk absolve Karius of blame|
|We all know where our nipples are - Hansen welcomes tackle trial|
|Rooney would thrive in MLS, says DC United boss|
|Pakistan complete demolition of sorry England|
|Curry, Durant reveal the secret to Thompson´s success|
|Salah will miss World Cup, claims Saudi sports administrator|
|Deschamps marvels at Zidane´s incredible Champions League success|
|FIA satisfied Ferrari ´inside the rules´|
|NSW Origin hopeful Moylan pulls the strings for rampant Sharks|
|Champions League blunders will stay with Karius - Clemence|
|Warriors assuming Iguodala won´t play game seven, Kerr says|
|Lampard confirms Derby talks over vacant managerial position|