Serbian world number one Novak Djokovic continued his unbeaten run over Italian Andreas Seppi to reach the fourth round at the Australian open on Friday.

The 10-time Grand Slam champion survived two set points in a final set tiebreaker before completing a 6-1, 7-5, 7-6 (8/6) win and his 12th straight over Seppi, and will now play Frenchman Gilles Simon.

The Serb world number one said it was almost the case that if he didn't win a title or make a final it is considered a failure, given his dominance of men's tennis.

"I think because of the very high standard that you set yourself with great results over the years, you expect from yourself a lot," Djokovic told reporters.

"It's true that the more you win actually the higher expectations are from yourself and from others.

"It's almost like after the 2015 season that I've had, anything aside from a title or a final is not a success.

"I still feel like I can do more. So that's something that keeps me going."

- Italian job -Djokovic has now reached the round of 16 at the Australian Open for a 10th straight year. The world's top player also holds a 33-match winning sequence against Italian opposition.

Djokovic was facing two set points in a third-set tiebreaker before he reeled off four straight points to take the match in two hours, 21 minutes. He is yet to drop a set in three rounds at the year-opening Grand Slam.

"I served my way out of trouble several times. But certainly I must be pleased with a straight sets win because both sets, especially the third, could have gone a different way," he said.

"But I'm still not very satisfied with certain parts of the second and third sets. I think I could have done better.

"But, again, I played a quality player who took out Roger Federer last year here and who has been on the tour for many years."

Djokovic whistled through the opening set, with two service breaks in just 25 minutes, but he encountered stiffer opposition in the following set.