What next for Denis Istomin? Well he'll face Pablo Carreno Busta in the third round, with the Spaniard having knocked out Britain's Kyle Edmund earlier.
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Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
Let's just take a moment to appreciate that Denis Istomin win.
Ranked 117 in the world and a wildcard entry for the Australian Open, no one expected the 30-year-old to step out onto the Rod Laver Arena and shock six-time winner Novak Djokovic.
It was a mammoth, energy-sapping effort in five sets and nearly five hours of tennis, too. In fact, Istomin felt the need to apologise to Djokovic for being on such form today.
Having lost back-to-back sets after winning the opener, the Uzbek could have been forgiven for thinking the momentum was with the world number two and defending champion, but he turned it around to take what he called the "biggest win" of his career.
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Murray's year?
Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
So what does that result mean for Andy Murray?
Well, six-time winner Novak Djokovic was surely considered world number one Murray's biggest threat to winning a first Australian Open title.
The Scot's lost five finals in the past seven years - four of which were to Djokovic - in Melbourne, but with the defending champion out, it might just be Murray's time...
From losing to the world number 211 to beating the world number two...
'It means so much to me'
Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
World number 117 Denis Istomin on his win against Novak Djokovic: "I was playing so good today. I surprised myself as well today. I want to thank my team, mum, you do a good job.
"So much emotion on my mind, I cannot hold it. But I want to say thank you for coming to support me. From the third set I had cramp in my leg, I don't know how I held it.
"It is the biggest win (of my career) for me and means so much, now I feel I can play with these guys and be with them on the same level."
ReutersCopyright: Reuters
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Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
That's fantastic from Denis Istomin, surely the win of his career.
As for Novak Djokovic, he departs the Rod Laver Arena to huge cheers from the Melbourne crowd, but the world number two is out in four hours and 48 minutes.
Game, set and match - Istomin beats Djokovic
Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
Wow!
Another big, big serve from the wildcard world number 117 and he's beaten the six-time Australian Open champion!
ReutersCopyright: Reuters
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*Djokovic 6-7 7-5 6-2 6-7 4-5 Istomin
Istomin watched that forehand Djokovic approach, leaned forward and fired in one of his trademark backhands, but this time it's wide.
His next serve is huge though - and that's two match points...
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*Djokovic 6-7 7-5 6-2 6-7 4-5 Istomin
So, four hours and 47 minutes into this second round match it's Denis Istomin who has the chance to serve for what would be the upset of the tournament.
The wildcard uses that backhand to great effect again as Djokovic can only reply with a weak forehand into the net, and the Serb finds the net again as the world number 117 moves to 30-0.
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Djokovic 6-7 7-5 6-2 6-7 4-5 Istomin*
Denis Istomin sends a backhand long after taking the opening point and has a little chuckle to himself, another long backhand follows and this time he's visibly frustrated.
Novak Djokovic makes its 40-15 and then takes the game to leave Istomin having to serve out for the match.
Post update
Djokovic 6-7 7-5 6-2 6-7 3-5 Istomin*
BBC Radio 5 live
If you want to listen in to this cracker, then we've got online only radio coverage available via the link at the top of the page.
Challenge
*Djokovic 6-7 7-5 6-2 6-7 3-5 Istomin
Novak Djokovic is staring at the baseline in front of him in disbelief, Denis Istomin is catching it almost every time and giving the Serb little room to find a winner.
He goes 30-0 on serve before challenging a huge, huge serve that he felt caught the corner of the service box - and he's got this one right as well!
And how about an ace to finish off? Istomin thinks he's got it, but that's a let...he was already walking.
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Djokovic 6-7 7-5 6-2 6-7 3-4 Istomin*
Well now it's Novak Djokovic cruising through a service game, and he'll be very thankful for a brief respite.
We've passed the four-and-a-half hour mark here. Djokovic makes it 40-0, before a ninth double fault cranks up the pressure a little.
His next serve is straight and powerful though, and Istomin can't muster a meaningful return on his inside.
EPACopyright: EPA
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Djokovic 6-7 7-5 6-2 6-7 2-4 Istomin*
And that's the game for Istomin. He polishes off this one with a couple of big serves that Djokovic has no answer to.
Fascinating stuff.
Challenge
*Djokovic 6-7 7-5 6-2 6-7 2-3 Istomin
Has that break rattled Djokovic? He's not won six Australian Open titles without having to dig deep a few times, but the Serb has only lost to a player ranked outside the top 100 once in the past seven years - that was to Juan Martin del Potro at last year's Olympics.
And with that, Istomin wins a challenge on his serve that was called out. Things are looking good for the 30-year-old Uzbek at the minute.
Istomin breaks
*Djokovic 6-7 7-5 6-2 6-7 2-3 Istomin
So Istomin comes up with another backhand that Djokovic is unable to return and that gives the world number 117 two break points.
Djokovic saves the first, but Istomin has him on the run for the second and then that formidable backhand comes into play once again with a winner down the line this time.
Live Reporting
Alex Bysouth and Mike Henson
All times stated are UK
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Latest Post'Read all about it'
If you want to read all about Novak Djokovic's exit and that surprise win for Denis Istomin, you can do here.
Want to recap on the rest of today's stories too? Well check these out:
And you can continue to follow all the action as it unfolds in Melbourne right here:
Until next time...
Post update
Busta up next for Istomin
What next for Denis Istomin? Well he'll face Pablo Carreno Busta in the third round, with the Spaniard having knocked out Britain's Kyle Edmund earlier.
Post update
Post update
Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
Let's just take a moment to appreciate that Denis Istomin win.
Ranked 117 in the world and a wildcard entry for the Australian Open, no one expected the 30-year-old to step out onto the Rod Laver Arena and shock six-time winner Novak Djokovic.
It was a mammoth, energy-sapping effort in five sets and nearly five hours of tennis, too. In fact, Istomin felt the need to apologise to Djokovic for being on such form today.
Having lost back-to-back sets after winning the opener, the Uzbek could have been forgiven for thinking the momentum was with the world number two and defending champion, but he turned it around to take what he called the "biggest win" of his career.
Post update
Murray's year?
Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
So what does that result mean for Andy Murray?
Well, six-time winner Novak Djokovic was surely considered world number one Murray's biggest threat to winning a first Australian Open title.
The Scot's lost five finals in the past seven years - four of which were to Djokovic - in Melbourne, but with the defending champion out, it might just be Murray's time...
Post update
Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
From losing to the world number 211 to beating the world number two...
'It means so much to me'
Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
World number 117 Denis Istomin on his win against Novak Djokovic: "I was playing so good today. I surprised myself as well today. I want to thank my team, mum, you do a good job.
"So much emotion on my mind, I cannot hold it. But I want to say thank you for coming to support me. From the third set I had cramp in my leg, I don't know how I held it.
"It is the biggest win (of my career) for me and means so much, now I feel I can play with these guys and be with them on the same level."
Post update
Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
That's fantastic from Denis Istomin, surely the win of his career.
As for Novak Djokovic, he departs the Rod Laver Arena to huge cheers from the Melbourne crowd, but the world number two is out in four hours and 48 minutes.
Game, set and match - Istomin beats Djokovic
Djokovic 6-7 7-5 6-2 6-7 4-6 Istomin
Wow!
Another big, big serve from the wildcard world number 117 and he's beaten the six-time Australian Open champion!
Post update
*Djokovic 6-7 7-5 6-2 6-7 4-5 Istomin
Istomin watched that forehand Djokovic approach, leaned forward and fired in one of his trademark backhands, but this time it's wide.
His next serve is huge though - and that's two match points...
Post update
*Djokovic 6-7 7-5 6-2 6-7 4-5 Istomin
So, four hours and 47 minutes into this second round match it's Denis Istomin who has the chance to serve for what would be the upset of the tournament.
The wildcard uses that backhand to great effect again as Djokovic can only reply with a weak forehand into the net, and the Serb finds the net again as the world number 117 moves to 30-0.
Post update
Djokovic 6-7 7-5 6-2 6-7 4-5 Istomin*
Denis Istomin sends a backhand long after taking the opening point and has a little chuckle to himself, another long backhand follows and this time he's visibly frustrated.
Novak Djokovic makes its 40-15 and then takes the game to leave Istomin having to serve out for the match.
Post update
Djokovic 6-7 7-5 6-2 6-7 3-5 Istomin*
BBC Radio 5 live
If you want to listen in to this cracker, then we've got online only radio coverage available via the link at the top of the page.
Challenge
*Djokovic 6-7 7-5 6-2 6-7 3-5 Istomin
Novak Djokovic is staring at the baseline in front of him in disbelief, Denis Istomin is catching it almost every time and giving the Serb little room to find a winner.
He goes 30-0 on serve before challenging a huge, huge serve that he felt caught the corner of the service box - and he's got this one right as well!
And how about an ace to finish off? Istomin thinks he's got it, but that's a let...he was already walking.
Post update
Djokovic 6-7 7-5 6-2 6-7 3-4 Istomin*
Well now it's Novak Djokovic cruising through a service game, and he'll be very thankful for a brief respite.
We've passed the four-and-a-half hour mark here. Djokovic makes it 40-0, before a ninth double fault cranks up the pressure a little.
His next serve is straight and powerful though, and Istomin can't muster a meaningful return on his inside.
Post update
Djokovic 6-7 7-5 6-2 6-7 2-4 Istomin*
And that's the game for Istomin. He polishes off this one with a couple of big serves that Djokovic has no answer to.
Fascinating stuff.
Challenge
*Djokovic 6-7 7-5 6-2 6-7 2-3 Istomin
Has that break rattled Djokovic? He's not won six Australian Open titles without having to dig deep a few times, but the Serb has only lost to a player ranked outside the top 100 once in the past seven years - that was to Juan Martin del Potro at last year's Olympics.
And with that, Istomin wins a challenge on his serve that was called out. Things are looking good for the 30-year-old Uzbek at the minute.
Istomin breaks
*Djokovic 6-7 7-5 6-2 6-7 2-3 Istomin
So Istomin comes up with another backhand that Djokovic is unable to return and that gives the world number 117 two break points.
Djokovic saves the first, but Istomin has him on the run for the second and then that formidable backhand comes into play once again with a winner down the line this time.
And a roar of approval to boot.