Serena Williams and Maria Sharapova showed why they are strong contenders for the Australian Open title as both made round three with convincing wins.
Five-time champion Serena outclassed Barbora Zahlavova Strycova 6-0 6-4 to set up a meeting with Greta Arn, who beat Dominika Cibulkova 2-6 6-3 8-10.
Sharapova was even more convincing in a 6-0 6-1 thrashing of Jamie Hampton and she will next play Angelique Kerber.
Petra Kvitova, Vera Zvonareva and Ana Ivanovic also went through on Thursday.
Wimbledon champion Kvitova was out of sorts and needed one hour and 47 minutes to complete a 6-2 2-6 6-4 victory over Spain's Suarez Navarro.
"It was okay at the beginning but then I made many, many mistakes," said the second seed, who fell behind in the third set before bouncing back.
Kvitova will hope to improve against 27th seed Maria Kirilenko, who overcame a second-set slump to beat the unseeded Canadian Aleksandra Wozniak 6-4 1-6 6-2.
Seventh seed Zvonareva, a semi-finalist in 2009 and 2011, beat Lucie Hradecka 6-1 7-6 (7-3) and faces compatriot Ekaterina Makarova for a place in the last 16 after Makarova upset 25th seed Kaia Kanepi of Estonia 6-2 7-5.
Sharapova opened play on Rod Laver Arena but needed only 64 minutes to dispatch her American opponent.
"I didn't know too much about my opponent so I just focused on myself and tried to improve on my first round," said the three-time Grand Slam champion.
She takes on Kerber on Saturday after the 30th seed from Germany overcame Canada's Stephanie Dubois 7-5 6-1.
Sharapova was followed on court by Serena and the 12th seed snapped up the first set against a forlorn Strycova in 22 minutes.
The Czech gave a better account of herself in the second, breaking Serena's serve in game nine to make it 4-5.
But the US number one hit straight back to secure a 68-minute triumph, the 500th win of her career.
Serena, who pulled out of the recent Brisbane International after rolling her ankle on court, fell awkwardly in the final game against Strycova but later said: "It's fine, I just have really wobbly ankles. I wasn't meant to be a ballerina."
A resurgent Ivanovic - now coached by former British Fed Cup captain Nigel Sears - made serene progress.
The 21st seed beat Michaella Krajicek 6-2 6-3 and next up is Vania King, who beat 15th seed Anastasia Pavlyuchenkova of Russia 7-5 3-6 4-6.
Marion Bartoli was another seed to comfortably progress, the ninth seed beating Jelena Dokic 6-3 6-2, while 14th seed Sabine Lisicki saw off Shahar Peer 6-1 6-2.
Meanwhile, 29th seed Nadia Petrova departed the tournament after a 6-2 6-2 loss to Sara Errani.