Jelena Dokic crashed out of game, while Roger Federer, Andy Roddick, Caroline Wozniacki, Venus Williams, Justine Henin and Li Na on Wednesday beat their opponents and reach third round of Australian Open.
World No.2, Federer who has reached at least the quarter-final of every grand slam event since the 2004 French Open, advanced to the third round with a 2-6 3-6 6-4 6-4 3-6 victory against Frenchman Gilles Simon in a three hours and 13 minutes match.
"He's a great player first of all so matches against him are never easy," Federer told reporters in Melbourne after the match. "This is the first win I've had against him, every time we played we go the distance, so hopefully we don't play each other any more."
In two previous meetings, Federer had not yet defeated Simon although neither of those matches was in a Grand Slam.
The 16-time major champion set a meeting with Belgiuan Xavier Malisse in third round.
World No.8 American Andy Roddick cruised into third round with a 7-6 (9-7) 6-2 6-3 win over Russia's Igor Kunitsyn at Rod Laver Arena in Melbourne.
After three days play at the 2011 Australian Open only five Americans remain in either men's or women's singles, and the 28-year-old Roddick was the last American man to win a Grand Slam at the 2003 U.S. Open.
Roddick will face Robin Haase from Netherlands in third round.
In the women's draw, No.1 seed Danish Caroline Wozniacki continued untroubled on her path to a first major title, with a an almost flawless 6-1, 6-0 over American Vania King win in just 58 minutes.
Wozniacki said there was plenty to be pleased with regarding her performance. She will face 32 seed Slovakian Dominika Cibulkova in next match.
Fourth seed Venus Williams has staged a remarkable comeback, overcoming injury to win her way through to the third round of the Australian Open.
A seven-time Grand Slam champion, Williams was forced to call for an injury timeout after losing the first set. She then battled back from a groin injury to oust Czech Sandra Zahlavova 6-7 (6-8) 6-0 6-4.
"This is probably the most acute one I've had," Williams said. "In recent times it's been one of the toughest ones for sure but I just wanted to stay on court and survive.
"Obviously I wasn't able to play at my exact level so I had to play smarter and hang tough."
She will face German Andrea Petkovic next.
The 11th-seeded Henin, who took the Australian title in 2004, served beautifully throughout the match to completely control the second round encounter.
She defeated Britain's No.1 Elena Baltacha 6-1, 6-3 in 61 minutes to set a meeting with Russian Svetlana Kuznetsova on Friday' s third round.
Meanwhile, World No. 11 and recent Medibank International champion, Li Na from China has cruised through to the third round at Australian Open 2011 with a 6-3, 6-2 victory over Russian Evgeniya Rodina.
She will next face unseeded Barbora Zahlavova Strycova of the Czech Republic, who put an end to Australian Jelena Dokic's Australian Open 2011 campaign after beating the Australian 7-6(3), 6-1.