NOVAK Djokovic today dismissed suggestions of invincibility after racking up another straightforward victory at the Australian Open.
The world number one lost just once in the four grand slams in a remarkable 2011 - to Roger Federer at the French Open - and also claimed a record five 1000 Masters Series events.
He was never threatened in easing into the third round in Melbourne this afternoon thanks to a straightforward 6-3 6-2 6-1 victory over Colombian Santiago Giraldo.
Asked afterwards whether he felt invincible, Djokovic replied: "I don't think anybody is invincible’’.
Djokovic dropped his serve early on but that proved the only blip as he cruised through to a last-32 clash with Frenchman Nicolas Mahut.
The Serbian did not play a warm-up event but has looked solid so far in Melbourne and admitted he was delighted to have kept plenty back for the challenges which lie ahead.
Andy Murray, the fourth seed and beaten finalist here in each of the past two years, enjoyed a routine 6-1 6-4 6-4 victory over Edouard Roger-Vasselin.
It was a much-improved display from Murray compared to his first-round struggles against American Ryan Harrison. He will next meet Roger-Vasselin's French compatriot Michael Llodra.
The Scot said: "I hit the ball better tonight although it was different conditions, much cooler. And when the shadow comes across the court it plays much slower which is easier.
"I was playing closer to the baseline from the beginning of the match as well."
Also winning through today was sixth seed Jo-Wilfried Tsonga, a 7-5 6-4 6-4 victor over Brazil's Ricardo Mello.
The Frenchman was a runner-up here in 2008 and semi-finalist two years ago, and he admitted he also enjoys playing in Melbourne.
"The conditions here are good for me," he said. "And it's pretty warm.
"The surface also, it's not really quick so maybe it's good for my game."
Ninth seed Janko Tipsarevic overcame a first-set scare to see off Australian wild card James Duckworth 3-6 6-2 7-6 (7/5) 6-4 while David Ferrer, the fifth seed, was pushed even further before eventually dismissing Ryan Sweeting 6-7 (4/7) 6-2 3-6 6-2 6-3.
Milos Raonic beat Philipp Petzschner 6-4 5-7 6-2 7-5, Mahut beat Tatsuma Ito 1-6 7-6 (8/6) 6-2 6-2 and Richard Gasquet moved on after Andrey Golubev had to retire when 6-4 6-2 3-0 down.
Lleyton Hewitt won the battle of the old stagers after Andy Roddick had to retire when two-sets-to-one down.
The American won the first set but injured his leg when stretching for a wide ball at 2-0 in the second.
Hewitt took full advantage and won the next two 6-3 6-4, at which point Roddick offered his hand.
"It was a nightmare for both of us," said Hewitt.
"Obviously Andy stretched something and it's hard to concentrate for the player up the other end.
"Andy is such a great fighter so you know when he is struggling.
"I don't want to sound cruel but you just try to run him around a bit more. We are out here competing, it's hard work."
Gael Monfils, the 14th seed, also progressed late on after beating Thomaz Bellucci 2-6 6-0 6-4 6-2 while Julien Benneteau won the all-French battle against 12th seed Gilles Simon 7-5 7-6 (10/8) 1-6 3-6 6-2 in over four hours.