Australian Open: 117-ranked Denis Istomin causes major upset, defeats defending champion Novak Djokovic

World number two Novak Djokovic suffered a shocking defeat when unseeded Denis Istomin of Uzbekistan rose to the occasion and won the second round of men's singles at the Rod Laver Arena.

World number 117 Istomin defeated defending champion Djokovic 6-7(8), 7-5, 6-2, 6-7(5), 4-6 in a five-set long match that ran for four hours and forty-eight minutes.

After winning the match, Istomin said even he was surprised with his performance.

"I feel sorry for Novak, I was playing so good today. I surprised myself today. I want to thank my team, my mum. You do a good job. Since the third set, I had cramp in my leg. I didn't know how I could hold it," Denis Istomin said. It is only the third time that Istomin has made it to the third round.

The Serb, Djokovic, on the other hand, has won the season's first Grand Slam as many as six times.

Istomin will now face Pablo Carreno Busta, the 30th seed, on Saturday in the third round.