Rafael Nadal, Andy Murray and Roger Federer are all safely through to the third round of the Australian Open but Juan Martin Del Potro is out.

Nadal and Federer found themselves playing at exactly the same time, under the roofs on Rod Laver and Hisense Arena.

And, after starting their matches together, they also finished them within a couple of minutes of each other, both securing straight-sets wins.

Top seed Nadal faced the lowest-ranked player in the draw, 17-year-old Thanasi Kokkinakis, the world number 570.

The Australian gave a very good account of himself but, not surprisingly, found Nadal too tough, the Spaniard winning 6-2 6-4 6-2.

Federer raced through the first two sets against Slovenian Blaz Kavcic but was given a tougher test in the third before coming through 6-2 6-1 7-6 (7/4).

The sixth seed had been 3-0 down in the tie-break but Kavcic rather blew his opportunity and then failed to pull off two consecutive diving volleys on match point.

Remarkably, it was the first match Federer had played away from Rod Laver Arena, Melbourne Park's centre court, for ten years.

The Swiss joked he headed out early to make sure he did not get lost, but said: "It was nice, I enjoyed it.

"It's not really different to Rod Laver Arena. The dimensions feel the same. I don't feel like you need to make an adjustment. The crowds were really nice. It was a great atmosphere over there. I was happy playing there."

The extreme heat policy was in operation while Federer and Nadal were playing after temperatures peaked at 43.4C.

That meant play was suspended on the uncovered courts, with Federer revealing he was not allowed to practise outdoors.

Nadal was more than happy to play indoors and was very impressed with his young opponent.

He said: "Even if that's his ranking, when you are playing against a young player, you never have that feeling. He was able to win the first round against a tough opponent like (Igor) Sijsling. That's not the real ranking on him.

"He played juniors, made two finals of grand slams last year, so he has a great future. He has the right level to try to be on the tour very soon. So he just has to keep working and that will happen."

Andy Murray recovered from a third-set wobble to defeat qualifier Vincent Millot.

The fourth seed was not at his best in very humid conditions under the lights on Rod Laver Arena and, after two comfortable sets, surprisingly found himself 5-1 down in the third.

But he saved a set point and reeled off six games in a row to triumph 6-2 6-2 7-5 and set up a third-round clash with Spain's Feliciano Lopez.

Tenth seed Jo-Wilfried Tsonga is a potential fourth-round opponent for Federer and he was in fine form in a 7-6 (8/6) 6-4 6-4 win over Thomaz Bellucci.

Japan's Kei Nishikori, the 16th seed, raced through against qualifier Dusan Lajovic while Donald Young upset Lleyton Hewitt's conqueror Andreas Seppi in five sets.

Young, once the great hope of American tennis, is through to the third round of a grand slam for the first time since the US Open in 2011.

Meanwhile, eighth seed Stanislas Wawrinka was handed a place in the fourth round after opponent Vasek Pospisil withdrew ahead of their scheduled match on Friday with a back injury.

Juan Martin Del Potro became the first major casualty in the Australian Open men's draw when he was beaten 4-6 6-3 5-7 6-4 7-5 by Spain's Roberto Bautista in the second round.
The fifth-seeded Argentine had shown signs that he might be returning to his best form with victory in the warm-up tournament in Sydney but succumbed in a three-hour 53-minute thriller on court two.
The extreme heat kept the former US Open champion and his 62nd-ranked opponent off court until 9.25pm local time and they treated the crowd to an exciting match in which they combined for 100 unforced errors and 125 winners.
Bautista went for his shots to win the latter count 72-53 and took his place in the third round at a grand slam tournament for the first time when the exhausted world number five netted. 

Gael Monfils will play Nadal in what is sure to be a crowd-pleasing third-round tie after beating American Jack Sock while there were also wins for Grigor Dimitrov, Milos Raonic and Gilles Simon.