Maria Sharapova followed Serena Williams out of the Australian Open in the fourth round, losing 3-6, 6-4, 6-1 to Dominika Cibulkova on Monday in the second major upset in 24 hours on Rod Laver Arena. Third-seeded Sharapova struggled with her serve, getting broken four straight games after failing to serve out the first set. Top-ranked Williams was knocked out in a three-set loss to 14th-seeded Ana Ivanovic on Sunday, and later revealed she had a back problem that had her considering withdrawing from the tournament. The absence of two of the biggest stars in women's tennis opens up the draw for two-time defending champion Victoria Azarenka, who was playing No. 13-seeded Sloane Stephens later Monday. More...