Maria Sharapova crashed out of the Australian Open in another seismic shock today as Rafael Nadal, Roger Federer and Victoria Azarenka saw off challenges to keep their title bids intact.
A day after Serena Williams' exit, Dominika Cibulkova kept the upsets rolling as she ousted injury-compromised Sharapova 3-6, 6-4, 6-1, blowing the women's draw even further open.
The main expected beneficiary, two-time defending champion Azarenka, is in position to take full advantage after she flattened old foe Sloane Stephens 6-3, 6-2 to reach the quarter-finals.
The Belarusian world number two will face either Agnieszka Radwanska or Garbine Muguruza in the quarter-finals, with Cibulkova heading into a clash with Romania's Simona Halep.
Men's top seed Nadal weathered a sustained assault from Japan's Kei Nishikori 7-6 (7/3), 7-5, 7-6 (7/3) to face Grigor Dimitrov in the Bulgarian's first Grand Slam quarter-final.
The 13-time Grand Slam-winner chided the umpire after he was called for a time violation, for taking longer than the allowed 20 seconds between points, at a critical moment in the third set.
"The negative thing in my opinion is not the warning, but the timing of it. You can choose another moment to do it, not that one," Nadal said.
Wimbledon champion Andy Murray needed five match points and four sets -- and angrily demolished a racquet along the way -- before beating 'lucky loser' Stephane Robert.
Murray cruised through the first two sets but he missed match points, and then dropped his first set of the tournament, before finishing it off 6-1, 6-2, 6-7 (6/8), 6-2.
"He's a fun player to watch but not fun to play against," said Murray, as Robert milked applause from the crowd. "He made it very tricky for me, he plays all the shots very unorthodox."
Federer, meanwhile, was a convincing winner against Jo-Wilfried Tsonga, racing through 6-3, 7-5, 6-4 to set up a quarter-final against Murray.
