Australian Open: Rattled Djokovic still the man to fear

Novak Djokovic is human after all.

Given his start to the year, which included rolling to the Doha title, Sunday's display at the Australian Open never looked on the cards.

The world number one delivered a century of unforced errors.

But Djokovic and his mistakes still managed to get past Frenchman Gilles Simon 6-3 6-7 (1-7) 6-4 4-6 6-3.

That he still progressed to a 27th straight grand slam quarter-final is perhaps a worrying sign for his rivals.

But last-eight opponent Kei Nishikori could barely have asked for more.

It took over four and a half hours and it was a gruelling baseline battle filled with long games and longer rallies.

Confidence will have taken a small hit - it had to at some point - and slight questions have arisen.

Is he ready for more of the same? Or another four hours worth?

If anyone is, it is Djokovic.

The 10-time grand slam champion barely showed signs of fatigue, brain snap drop-shots aside.

"It's not easy when you're not feeling the ball well and when you're not moving that great. When you're playing someone like Simon, he senses that and he makes you play an extra shot," Djokovic said.

"Then you're trying to cut down on the length of the rallies, go for a winner or go for a drop-shot.

"Sometimes you have a brain freeze, if I can call it that way. That's what happened to me many times with those drop-shots."

Djokovic may be hurting and a repeat performance is almost impossible, but that is better for his rivals than him looking unstoppable.

This was the man whose performance in the Doha final was described as perfection by Rafael Nadal, who was on the receiving end of the 6-1 6-2 scoreline.

He is human, in the quarter-finals and shaken, but beware the rattled giant.