Maria Sharapova continues her impressive run at the 2013 Australian Open, with a clinical 6-1, 6-0 defeat of unseeded Belgian Kirsten Flipkens. The second seeded Russian will now face compatriot Ekaterina Makaraova  after she upset fifth seed, German Angelique Kerber.
Sharapova has been in devastating form so far this tournament and has yet to drop a set in her progress to the quarter-final. In addition, the 25-year-old former world No 1 has lost only five games so far, four of which were to another former world No 1 - American Venus Williams .
The morning session at Melbourne also saw men's fourth seed, David Ferrer of Spain, register a comfortable 6-2, 6-1, 6-4 win over Japan's Kei Nishikori . The 30-year-old Ferrer will now play compatriot Nicolas Almagro  in the quarter-final. Almagro beat eighth seed Janko Tipsarevic after the Serbian retired trailing 1-5, 2-6.
Meanwhile, men's doubles top seeds, Bob and Mike Bryan, marched on to the quarter-final, with a three-set win over unseeded French-Polish pair of Jeremy Chardy and Lukasz Kubot. The Bryans will face Daniel Bracciali of Italy and Lukas Dlouhy of the Czech Republic next.
The top seeds in the women's doubles are also through to the next round. Sara Errani and Roberta Vinci of Italy beat Su-Wei Hsieh of Taipei and Shuai Peng of China  6-4, 0-6, 7-5 and will face 12th seeds Venus and Serena Williams of the US.
There were minor upsets in the doubles competitions, with sixth seeds Aisam-Ul-Haq Qureshi of Pakistan and Jean-Julien Rojer of the Netherlands crashing out of the men's competition to Thomaz Bellucci of Brazil and Benoit Paire of France. And the sixth seeds in the women's doubles event also lost; the unseeded Spanish pair of Silvia Soler-Espinosa and Carla Suarez Navarro beat Liezel Huber of the US and Maria Jose Martinez Sanchez of Spain 7-6(5), 2-6, 6-4 to set up a meeting with either the fourth seeded Russian pair of Ekaterina Makarova and Elena Vesnina or 13th seeds Irina-Camelia Begu and Monica Niculescu of Romania.