Sharapova out in another early upset in Australia

MELBOURNE, Australia — 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. After taking an off-court medical time out after the second set for what appeared to be a lower back problem, she had seven double-faults in the third set.

The four-time major winner was two tournaments into a comeback from a prolonged layoff with a right shoulder injury.

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.

Sharapova made it hard for herself in Australia, having difficulty closing out her second- and third-round matches. She needed almost 3 ½ hours to beat Karin Knapp in searing heat the second round — playing 50 minutes before her first and final match points.

Cibulkova had spent just over 3½ hours on court in her first three wins, including a 6-1, 6-0 win over No. 16 Carla Suarez Navarro in the third round.

The pair hadn't played since Sharapova's quarterfinal win at Wimbledon in 2011. Now they're evenly split in six head-to-heads.

Cibulkova raced to a 5-0 lead in the second set before tightening up and letting Sharapova back into the match. She was more steady in the third, when she didn't even face a break point.

"I was never doubting myself," the No. 20-seeded Cibulkova said, adding that Ivanovic's win over Williams the previous day had been motivational but not her main inspiration against Sharapova.

"It was a great match for Ana. But this was a different story. I already beat Maria before and I beat her" at a major.