Defending champion Novak Djokovic crashed out of the Australian Open after falling victim to a stunning five-set defeat at the hands of wild card Denis Istomin.
Djokovic was chasing a record seventh title in Melbourne, but his pursuit is over for another year after Istomin, ranked 117th in the world, edged a mammoth contest 7-6 (10/8) 5-7 2-6 7-6 (7/5) 6-4.
It means after winning four consecutive grand slams between 2015 and 2016, Djokovic has now gone three tournaments without adding to his tally of 12 major triumphs.
Istomin, meanwhile, goes through to face 30th seed Pablo Carreno Busta in round three.
The 30-year-old has never before gone past the fourth round of a major tournament and this is only his second win in 34 career matches against a top-10 player.
Istomin, however, played the match of his life on Rod Laver Arena, hitting 63 winners, breaking Djokovic four times and showing remarkable resilience when his more distinguished opponent regularly threatened to take hold.
"I'm sorry for Novak," he said on court afterwards.
"I was playing so well today. I surprised myself as well.
"It was a tough third set, I had cramp in my leg, I don't know how I held it. I was physically normal today.
"It is the biggest win for me, it means so much. It shows I can play with these guys and be on the same level."
#Djokovic press conference "he was better" #AusOpen pic.twitter.com/PRULPn33TY
— #AusOpen (@AustralianOpen) January 19, 2017
Istomin, with his fluorescent yellow headband and glasses, is an experienced member of the men's tour but when Djokovic was beating Andy Murray to win the Qatar Open earlier this month, the Uzbek was losing to Chile's Christian Garin, ranked 211th in the world, at a Challenger event in Thailand.
It adds another chapter to Djokovic's recent demise given the 29-year-old had hoped the new season would be a point to revive his form but has merely proven a continuation of last year's disappointments.
"There was intensity, of course," Djokovic told reporters.
"We played four-and-a-half hours. It's just that, you know, it's one of these days when you don't feel that great on the court, don't have much rhythm, and the player you're playing against is feeling the ball very well.
"So, you know, that's sport. I started the season very well. Again, it's a tennis match. On a given day, you can lose. I mean, nothing is impossible.
"What can I do? I did try my best till the last shot, but it didn't work."
Rafael Nadal raised hopes of filling the power vacuum left by Djokovic's exit after demolishing Marcos Baghdatis 6-3 6-1 6-3 to reach the third round.
Djokovic loomed as a potential semi-final opponent for Nadal but the Serb's five-set upset by Istomin shook up the draw and left the Spaniard as the sole grand slam champion in the bottom half.
Nadal has had two lean years at the majors, but on the same Rod Laver Arena where Djokovic fell to Istomin, the 14-times major champion showed enough of the old passion and firepower to suggest he may yet go deep in the second week at Melbourne Park.
"What Novak did here is just amazing," said Nadal, paying tribute to the fallen 'Big Four' colleague who edged him in an epic for the 2012 title, the longest grand slam final played.
"Six victories here, six titles. For a lot of years he has been in the semi-finals, finals, and winning here. So it's normal then (to lose). It's not possible to be every time in that situation."
Nadal needed only two hours and 13 minutes to defeat Cypriot Baghdatis, whose run to the 2006 final as an unseeded 20-year-old is part of Australian Open folklore.
The 31-year-old Baghdatis saved two match points but Nadal closed out the one-sided contest with a smoking cross-court forehand, his 32nd winner for the match, and punched the air in triumph as the terraces roared.
Nadal, 30, faces German talent Alexander Zverev next, a player tipped for a big future in the game.
Meanwhile, third seed Milos Raonic continued his machine-like advance, easing past Gilles Muller 6-3 6-4 7-6(4) to reach the third round.
The big-serving Canadian, a semi-finalist at Melbourne Park last year, was clinical on a sun-bathed Margaret Court Arena, firing 21 aces and breaking the serve-volleyer from Luxembourg once in each of the first two sets.
Left-hander Muller, who celebrated his maiden ATP title in Sydney earlier this month in his 17th year as a professional, saved a match point in the decisive tiebreak but fired a forehand into the tramlines to bow out.
Raonic will next play French 25th seed Gilles Simon for a place in the fourth round.
Milos #Raonic to face Gilles #Simon in 3R #AusOpen pic.twitter.com/8bs3Sm0MFH
— #AusOpen (@AustralianOpen) January 19, 2017
Kyle Edmund's campaign came to a tame end as he was outclassed 6-2 6-4 6-2 by Spain's Pablo Carreno Busta in the second round.
Edmund received treatment during the first set and struggled with his serve - the Melbourne sun appearing to hamper him during the latter stages of the contest - as well as squandering all six of his break points.
In contrast 30th seed Carreno Busta barely put a foot wrong, dismantling his opponent in an hour and 46 minutes.
