Rafael Nadal fought off the challenge of teenage Australian Thanasi Kokkinakis to reach the third round of the Australian Open.

The match pitted the highest-ranked player in the draw against the lowest, with 17-year-old Kokkinakis the world number 570.

But he showed in his first grand slam win against Igor Sijsling in the opening round that he will not be at that ranking for long.

And, although he went down to a 6-2 6-4 6-2 defeat by world number one Nadal, it was another hugely impressive performance from the teenager.

Kokkinakis did not appear fazed by playing the top seed on Rod Laver Arena, which had its roof shut because of the extreme heat.

He paid the price for dropping serve early in each set, but could well have got back into the second, with Nadal saving all three break points he faced.

The Spaniard complained about the pace of the courts before the tournament but looked in fine fettle ahead of a potential third-round meeting with France's Gael Monfils.