(Reuters) - Budding Hollywood actor Novak Djokovic led the way with a 6-3, 6-2, 6-1 demolition of Santiago Giraldo as a trio of former Australian Open champions reduced their opponents to bit-part characters on Thursday.

Djokovic makes his acting bow in the blockbuster The Expendables 2 later this year but the defending champion showed he had lost none of his appetite for the day job with an emphatic second-round victory at Melbourne Park.

Maria Sharapova and Serena Williams earlier swept into the third round to rumblings about the lack of depth in the women's game but second seed Petra Kvitova bucked the trend when her match threatened to turn into a horror show.

Scot Andy Murray, the losing finalist for the last two years here, was also in imposing form and there was no need for any Braveheart-inspired heroics as he dispatched Frenchman Edouard Roger-Vasselin 6-1 6-4 6-4.

Djokovic revealed that he gets into a fight in his movie debut and, if the first film in the series is anything to go by, it is likely to be more of a dramatic tussle than the crowd on Rod Laver Arena witnessed on Thursday.

A win is a win however it comes to you. I try obviously to not underestimate any opponents in early rounds, the Serbian told reporters.

Santiago came out early hitting the ball quite flat but I knew that sooner or later he's going to drop the rhythm and I just have to hang in there. I've done a good job.

There was a brief blip in the first set, when four unforced errors handed Giraldo a service break, but the world number one broke back to love immediately and said there had been no nerves.

To be honest, I've had lots of situations where I was break down in my career so I guess that doesn't affect me, especially early in the first set, he said. I knew that I would start hitting the ball better.

Sharapova, the 2008 champion, took just 64 minutes to crush American qualifier Jamie Hampton 6-0 6-1, while five-times winner Williams needed two minutes more to defeat Czech Barbora Zahlavova Strycova 6-0 6-4.

The third former winner in the women's draw, defending champion Kim Clijsters, progressed with a 6-0 6-1 victory on the same Rod Laver Arena on Wednesday.

While a dreaded double bagel 6-0 6-0 defeat has yet to be doled out this year, the rash of lop-sided contests has once again prompted questions about the gap in quality between the best and the rest in women's tennis.


The performance of Kvitova's 58th-ranked opponent Carla Suarez Navarro was a riposte to those questions, however, as she forced the Wimbledon champion to fight back from a break down in the third set to salvage a 6-2 2-6 6-4 win.

It's very tough to get back because you know that she moved very well and she got everything, the 21-year-old Czech said.

I just try to get more shots and be in the rallies with her and play smarter. That was the key.

When fit, Williams has often been at an elite level of her own over the years and her victory over Strycova was the 500th win of her career.

It's like the ultimate. It's really, really cool. Five hundred is a lot of matches to play, let alone to win, she said of the milestone, which only her sister Venus, Clijsters and Thai Tamarine Tanasugarn have reached before her among active players.

Murray was as delighted with his performance against Roger-Vasselin after dropping the first set in his opening match against Ryan Harrison.

I served well and didn't give him any chances, so was happy, said the Scot.

Roger-Vasselin aside, it was a fine day for France as sixth seed Jo-Wilfried Tsonga, Gael Monfils (14th), Richard Gasquet (17th), Nicolas Mahut, Julien Benneteau and Michael Llodra all reached the third round.

The locals had something to shout about at the end of the day when Lleyton Hewitt, the former U.S. Open and Wimbledon champion, progressed after 2003 U.S. Open winner Andy Roddick retired hurt when trailing 3-6 6-3 6-4.