It was a day that had a major upset with Serena Williams crashing out of the tournament after losing to Ana Ivanovic. (AP/AFP)
Ana Ivanovic came from a set down to win 4-6, 6-3, 6-3, ending Serena Williams' bid to match Chris Evert and Martina Navratilova with 18 Grand Slam titles.
Flavia Pennetta registered a hard-fought 6-1, 4-6, 7-5 win over Angelique Kerber in one hour 52 minutes.
Two-time Melbourne finalist Li Na brushed aside Russia's Ekaterina Makarova 6-2, 6-0 win in 59 minutes.
World No.2 Novak Djokovic, who is bidding for a fifth Australian title and his seventh Grand Slam, crushed Italian Fabio Fognini 6-3, 6-0, 6-2.
David Ferrer dropped the opening set in a tiebreaker before going on to win 6-7 (5/7), 7-5, 6-2, 6-1 in just under three hours on Hisense Arena.
Indo-Czech pair of Leander Paes and Radek Stepanek beat Yuki Bhambri and Michael Venus 6-3, 6-2 in the third round.
The seventh seeded pair of India's Rohan Bopanna and his Pakistani partner Aisam-Ul-Haq Qureshi endured a shocking defeat against the 12th seeded duo of Treat Huey and Dominic Inglot to crash out of the men's doubles event.
Mahesh Bhupathi and Elena Vesnina also entered the second round of the mixed doubles category.