- Top seed Caroline Wozniacki books her place in Australian Open second round
- Defending champion Kim Clijsters also through, alongside fifth seed Li Na
- Third seed Victoria Azarenka advances, as does Poland's Agnieszka Radwanska
- Italian 19th seed Flavia Pennetta beaten by Russian qualifier Nina Bratchikova
World No. 1 Caroline Wozniacki began her latest bid for a first grand slam title with a 6-2 6-1 win over Anastasia Rodionova on Monday, joining last year's finalists Kim Clijsters and Li Na in the second round of the Australian Open.
Top seed Wozniacki looked in good shape as she wrapped up victory against the Russia-born Australian in 76 minutes, but the Dane admitted she was worried about a wrist injury she suffered during last week's quarterfinal defeat at the Sydney International.
"I was a bit nervous before the match. I didn't know exactly what to expect. But it feels better," the 21-year-old told the WTA Tour website. "I'm very happy about the way I felt out there today. I got into the rhythm as the match went on tonight."
Wozniacki will next play Georgia's 83rd-ranked Anna Tatishvili, who beat Australia's Ashleigh Barty 6-2 7-6 (7-4).
Former No. 1 Clijsters made a strong start to the defense of her crown with a 7-5 6-1 defeat of Portuguese qualifier Maria Joao Koehler.
The Belgian 11th seed, who will play France's world No. 98 Stephanie Foretz Gacon in the last 64, showed little sign of the hip injury which forced her out of the Brisbane International 10 days ago.
"I wanted to go out there and I wanted to start playing," the 28-year-old told the tournament's official website. "I've had that ever since we came to Australia.
"I had a good off-season where we worked obviously to try to be in good shape for Australia, then you want to put that to the test and play those matches again."
Clijsters is on course for a fourth-round rematch with Chinese fifth seed Li, who eased through by beating Kazakhstan's world No. 40 Ksenia Pervak 6-3 6-1.
Li, who became Asia's first grand slam singles champion with her French Open triumph last year, struggled to handle the intense heat on court but emerged victorious to set up a clash with Australia's 168th-ranked 20-year-old Olivia Rogowska.
"I was feeling at end of the first set really hot on the court.," she said. "Also I was feeling no air. I couldn't breathe."
Third seed Victoria Azarenka of Belarus is through after an impressive 6-1 6-0 victory over Heather Watson of Britain in the opening match of the tournament.
The victory continued Azarenka's fine form coming into the tournament, having beaten Li in the final of the Sydney International on Friday. Her next opponent is Australia's Casey Dellacqua, who beat Serbia's Bojana Jovanovski 6-3 6-2.
Eighth seed Agnieszka Radwanska, a quarterfinalist in 2011, came from behind to eliminate American Bethanie Mattek-Sands.
The Pole's reward for a 6-7 (10-12) 6-4 6-2 success is a match with Argentine qualifier Paula Ormaechea, who claimed the first WTA Tour level match win of her career by beating 50th-ranked Romanian Simona Halep 6-1 3-6 7-5.
Italian 10th seed Francesca Schiavone also booked her place in the next round. The 2010 French Open champion disposed of Spain's world No. 72 Laura Pous-Tio 6-1 6-3, and will next play Romina Oprandi.
But their compatriot Flavia Pennetta made a shock early exit as the 19th seed lost 6-3 1-6 6-2 against Russian qualifier Nina Bratchikova.
China's 16th seed Peng Shuai is safely through thanks to a 6-3 6-4 win against world No. 120 Aravane Rezai. Peng will next play the Czech Republic's Iveta Benesova, who beat Rezai's fellow Frenchwoman Mathilde Johansson 6-3 2-6 6-4.
Former world No. 1 and 13th seed Jelena Jankovic progressed with a 6-2 6-0 demolition of Laura Robson, who was one of five British players to be eliminated in the men's and women's draws.
American Christina McHale earned a surprise 6-2 6-4 win over Czech 24th seed and 2007 Australian Open quarterfinal Lucie Safarova.
Belgian 28th seed Yanina Wickmayer, who won the the Hobart International title last week, lost 7-5 6-2 to Kazakhstan's 62nd-ranked Galina Voskoboeva.
Spanish 26th seed Anabel Medina Garrigues went through 6-3 6-3 against Czech Eva Birnerova, while Slovakian 20th seed Daniela Hantuchova recovering from dropping the opening set to Uzbekistan-born American Varvara Lepchenko to win 4-6 6-3 6-2.
German 22nd seed Julia Gorges also progressed along with Romania's No. 31 Monica Niculescu and Czech No. 32 Petra Cetkovska.