Novak Djokovic, David Istomin, Australia Open 2017, top seed, Djokovic lose
Novak Djokovic.Reuters

Defending champion Novak Djokovic received a major shock when the former World No. 1 tennis player was shown the exit door by Denis Istomin in the second round of the Australian Open. The two players were involved in an epic five-set battle, which lasted for four hours and 48 minutes. Istomin held his nerve to create the biggest upset of the competition so far, winning the contest 7-6, 5-7, 2-6, 7-6, 6-4.

However, Milos Roanic booked his spot in the third round while in the women's singles, Johanna Konta, Caroline Wozniacki and Dominika Cibulkova managed to reach the third round of the Australian Open.

Read how Federer, Wawrinka, Kerber reached third round

Djokovic was tested to the limit by Istomin, who looked in sparkling form from the first set itself. He matched Djokovic shot by shot, and the latter's fans were left shocked after the Uzbek player stunned the Serbian in the first set, winning it 7-6. Though Djokovic came with an improved performance and won the second set, Istomin challenged him from the baseline too. There was nothing to choose from between the two players. 

Djokovic did play his best game in the third set, where he looked convincing and comfortable. He dominated Istomin for the first time in the match to win it 6-2. After a cruising win in the third set, one expected Djokovic to finish the match in the fourth set, but Istomin won it via tie-break.

That Djokovic would be taken to a five-set match so early on in the competition wasn't expected by many. Istomin stretched him to length. The Uzbek player also showed some strong determination and calmness in the final set, which stood out while he was on way to his stunning fifth set win. The deciding set was always going to be tough, with both players getting involved in some amazing groundstrokes, and Istomin finally won 6-4. 

There were not many surprises in other men's singles matches. Third seed Raonic faced a tricky opponent in the form of Giles Muller, but the Canadian was in his zone from the first set itself. After winning the first two sets with decent ease, Raonic was tested in the third set, but he held his nerve to clinch the match in a tie-break, 6-3, 6-4, 7-6 (7-4)

Richard Gasquet also progressed into the third round after a clinical performance against Argentina's Carlos Berlocq. The Frenchman won in straight sets. Gasquet dominated the match and hardly let his guard down in his 6-1, 6-1, 6-1 victory. Gasquet will now meet Grigor Dimitrov, who defeated Hyeon Chung on Thursday. The score read 1-6, 6-4, 6-4, 6-4.

Eleventh seed David Goffin looked in good form in his second round match against Radek Stepanek and emerged triumphant in straight sets, 6-4, 6-0, 6-3.

In the women's singles, the seeded players were in full flow. Konta and Wozniacki entertained the crowd at the Rod Laver Arena. Both the players won their singles matches against Naomi Osaka and Donna Vekic, respectively, in straight sets. Konta won 6-4, 6-2 while Wozniacki emerged victorious 6-1, 6-3. It was with the same ease that Karolina Pliskova defeated Anna Blinkova 6-0-6-2 in 59 minutes.

However, it was not all too easy for the sixth seed Cibulkova against Su-Wei Hsieh. The two were involved in a tough battle, which lasted for 103 minutes on the court. The first set might have been easy for Dominika, but the Chinese Taipei player showed great form. Su-Wei Hsieh challenged her opponent, but could not cross the finishing line, losing the second set via a tough tie-break. It was a quality two-set affair, score reading 6-4, 7-6 (10-8).