Victoria Azarenka was the first woman to reach the quarterfinals, beating Iveta Benesova, 62 62.
Victoria Azarenka dropped the fewest games of anyone across the first four rounds - just 12 games.
Agnieszka Radwanska put on a sublime performance against Julia Goerges in her fourth round match.
Julia Goerges searched for answers during the first Grand Slam fourth round match of her career.
Agnieszka Radwanska made only three unforced errors during a 61 61 victory over Julia Goerges.
The stands filled up as Japanese icons Kimiko Date-Krumm and Kei Nishikori played mixed doubles.
On a day off between matches, Sabine Lisicki took part in a children's face painting activity.
Sabine Lisicki would eventually fall to Maria Sharapova in a riveting round of 16 clash, 36 62 63.
In perhaps the match of the tournament, Kim Clijsters survived Li Na in a thriller, 46 76(6) 64.
Li Na held quadruple match point leading 6-2 in the second set tie-break against Kim Clijsters.
Caroline Wozniacki calmly stormed out to a 60 41 lead against Jelena Jankovic on Sunday night.
Jelena Jankovic put up a lot of late resistance but still fell to Caroline Wozniacki, 60 75.
Petra Kvitova kicked off the Monday schedule with a 62 76(2) fourth round win over Ana Ivanovic.
Ana Ivanovic showed a lot of fight at the end, breaking at love with Petra Kvitova serving for it.
Petra Kvitova held on and played a perfect tie-break to reach her fourth Grand Slam quarterfinal.
Sara Errani continued her shock run through the draw, cruising past Zheng Jie in the 16s, 62 61.
Serena Williams has won more Australian Opens than anyone in the Open Era, but struggled Monday.
Ekaterina Makarova's big lefty game gave Serena Williams all kinds of trouble on Rod Laver Arena.
Serena Williams met Ekaterina Makarova at the net after a shock loss to the Russian, 62 63.
Serena Williams left the court. Williams had been 18-0 in her career against lefties at the Slams.