The Italian faces Romania's Monica Niculescu next after the 23-year-old beat 32nd seed Tsvetana Pironkova of Bulgaria 6-4 6-1.

BBC: Australian Open: Venus Williams labours to victory

German 22nd seed Julia Gorges also progressed along with Romania's No. 31 Monica Niculescu and Czech No. 32 Petra Cetkovska.

CNN: No. 1 Wozniacki wins Melbourne opener

"It definitely helped to bring a lot of inner confidence in myself, knowing that I can do it, " said the 23-year-old, who will play 54th-ranked Romanian Monica Niculescu.

CNN: Sharapova takes on Australian boys

The Dane, seeking a first grand slam title and needing to reach the last eight to have a chance of staying top of the rankings, beat Romanian 31st seed Monica Niculescu 6-2 6-2.

CNN: Clijsters faces Li in Aussie final rematch

Azarenka's first match is against Romania's Monica Niculescu.

CNN: Mathieu first up for Djokovic in Melbourne hat-trick quest

Fifth seed Stosur , who was runner-up to Schiavone at Roland Garros, came from behind to beat Elena Vesnina 3-6 7-6 (7-2) 6-1, and number 10 seed Azarenka overcame a blip to beat Monica Niculescu 6-0 5-7 6-1.

BBC: Venus Williams & Kim Clijsters into US Open round two