Top seed Caroline Wozniacki and defending champion Kim Clijsters both reached the third round of the Australian Open without hiccup.
Wozniacki overcame a late fightback from Georgia's Anna Tatishvili to secure a 6-1 7-6 (7-4) win.
Stephanie Foretz Gacon was thrashed 6-0 6-1 in 47 minutes by Clijsters who will next play Daniela Hantuchova.
Hantuchova beat Lesia Tsurenko, while Victoria Azarenka impressively beat Casey Dellacqua 6-1 6-0.
Third seed Azarenka, one of four players who could emerge from this tournament as world number one, was too good for world number 126 Dellacqua, with the 22-year-old's aggression and mobility proving too much for the Australian wild card.
Elsewhere, Li Na thrashed Olivia Rogowska 6-2 6-2, while the biggest shock of the day was the elimination of 10th Francesca Schiavone.
Italy's Schiavone was stunned by compatriot and world number 80 Romina Oprandi 6-4 6-3, later admitting it was a "really bad match".
The 2010 French Open champion, a quarter-finalist at Melbourne Park in 2011, succumbed in an hour and 24 minutes on Margaret Court Arena.
She finished with 20 winners compared to Oprandi's 15 but 35 unforced errors to 16 from the world number 80.
World number one Wozniacki made quick work of winning the first set 6-1 against Tatishvili, but found herself 4-1 behind in the second when her opponent began to play inspired tennis on her Australian Open debut.
The pressure soon told on Tatishvili, though, when a forehand sailed long when serving for the set at 5-3, which allowed the Dane to take the set to a tie-break.
Wozniacki will play Monica Niculescu of Romania, who beat France's Pauline Parmentier 6-4 4-6 1-6.
"I pulled through," said Wozniacki after completing the victory in 109 minutes. "I thought the first set I played pretty well, I stayed aggressive and made her run.
"In the second she went for more shots and I stepped back a little bit and she punished me for that."
Earlier on Wednesday, Iveta Benesova shocked 16th seed Peng Shuai 6-2 6-4.
Number 13 seed Jelena Jankovic looked out of sorts in the early stages against little-known Kai-Chen Chang but recovered to win 6-4 6-2.
"I started pretty slowly, I needed to figure out how to play her," said the former world number one from Serbia.
"I really didn't know her style of play. I had heard a few things from other players but I didn't know how I should strike ball.
"But I kept going, started to play well, stayed confident and after the first set it was a little bit easier."
Julia Goerges, seeded 22nd, was leading 6-2 2-0 when her opponent Eleni Daniilidou retired, and 26th seed Anabel Medina Garrigues beat Olga Govortsova 6-1 6-0.