- World No. 1 Novak Djokovic safely into the Australian Open second round
- Fourth seed Andy Murray recovers from losing the opening set to advance in Melbourne
- Spanish fifth seed David Ferrer advances along with sixth seed Jo-Wilfried Tsonga
- World No.9 Janko Tipsarevic battles to claim his place in the last 64
World No. 1 Novak Djokovic made a strong start to the defense of his Australian Open crown on Tuesday, and then backed growing calls for change in the men's tennis calendar.
The top seed powered past 109th-ranked Italian Paolo Lorenzi 6-2 6-0 6-0 in round one before echoing rival Rafael Nadal's sentiments that the busy ATP Tour schedule is having a negative impact.
"I don't think that whatever I will say will be something new, something that we don't know," the 24-year-old Serbian told reporters.
"It's obvious that there is a lot of players in men's tennis that are complaining about the schedule and season. They don't even need to say much.
"But just looking in the injuries that we have, especially from the top players, including myself, I felt that towards the end of last year, it's obvious that we need some change. But I prefer talking in detail about these things more behind closed doors."
Djokovic, playing in his first ATP Tour match this year, suffered an early setback as Lorenzi broke his serve in the third game to lead 2-1.
But the four-time grand slam winner recovered, winning 16 games in a row to wrap up victory in the scorching heat of the Rod Laver Arena in one hour and 32 minutes.
"Obviously, I want to get a good start of the year in my first official match of the season," Djokovic said. "I'm satisfied with the overall performance today. I think it was really the hottest day since I've arrived here.
"I just have more confidence that I'm playing on right now. I just believe that I can win, especially against the biggest rivals in the major events."
Djokovic will next play Colombia's 56th-ranked Santiago Giraldo, who beat Italy's Matteo Viola 6-4 6-2 6-1.
His opponent in last year's final, Andy Murray, was made to work hard for his place in the second round.
The British fourth seed came from behind to defeat American teenager Ryan Harrison 4-6 6-3 6-4 6-2 in three hours and 12 minutes at the Hisense Arena.
"He came out playing great tennis, going for his shots and hitting big," Murray, who was also runner-up in 2010, said of the 77th-ranked 19-year-old. "This court is tough -- there's very little shade.
"We had a few long rallies and he made me do a lot of running. I'll need to make sure in my next match that I play closer to the baseline."
Murray will next play France's world No. 101 Edouard Roger-Vasselin, who won the opening set of his match with 64th-ranked Xavier Malisse before the Belgian retired injured.
Fifth seed David Ferrer is safely through after a 6-1 6-4 6-2 win against Portugal's world No. 70 Rui Machado.
The Spanish Davis Cup winner's next opponent will be Ryan Sweeting, the 68th-ranked American who beat Germany's Matthias Bachinger 6-4 6-4 6-2.
French sixth seed Jo-Wilfried Tsonga fought his way to a 6-4 3-6 6-2 7-5 victory over Uzbekistan's Denis Istomin.
The 2008 runner-up set up a clash with 108th-ranked Brazilian Ricardo Mello, who defeated Spain's Roberto Bautista-Agut 6-4 6-4 7-5.
Tsonga was joined in the last 64 by Davis Cup teammates Gilles Simon, Gael Monfils and Richard Gasquet -- collectively known as "the New Musketeers" by the French media.
World No. 15 Monfils beat Australia's Marinko Matosevic 7-6 (7-5) 6-3 6-3 to earn a tie with Brazil's Thomaz Belluci, who eliminated Israel's Dudi Sela.
Simon, seeded 12th, emerged victorious from a five-set marathon against Thailand's world No. 201 Danai Udomchoke to set up a clash with compatriot Julien Benneteau.
Gasquet, the No. 17, will face Kazakhstan's Andrey Golubev after beating Italy's Andreas Seppi 6-3 3-6 6-3 6-1.
Serbian ninth seed Janko Tipsarevic lost the opening set to Russia's Dmitry Tursunov, but scrapped to claim a 5-7 7-6 (14-12) 6-3 6-4 success and a place in round two against Australia's 20-year-old debutant James Duckworth.
American Andy Roddick advanced with a 6-3 6-4 6-1 success over Dutch world No. 53 Robin Haase, and the 15th seed will next play fellow former world No. 1 Lleyton Hewitt of Australia.
The winner of that match will play either Canadian 23rd seed Milos Raonic or Germany's Philipp Petzschner in round three, with Djokovic looming after that.
Japan's 24th seed Kei Nishikoro also went through, and will play either Simon or Benneteau if he beats Australia's 94th-ranked Matthew Ebden.
Spanish 26th seed Marcel Granollers will play Tsonga or Mello if he defeats Portugal's Frederico Gil, while Argentina's world No. 29 Juan Ignacio Chela could face Ferrer if he gets past Spain's Pablo Andujar.
Czech 29th seed Radek Stepanek crashed out 7-5 7-5 6-3 against French world No. 81 Nicolas Mahut, who will likely face Djokovic in round three if he overcomes Japan's Tatsuma Ito.