Maria Sharapova tumbled to the tail end of the Top 10 in the latest WTA singles rankings released on Monday following the Sony Open in Key Biscayne.

Sharapova fell in the semifinals to eventual champion Serena Williams after reaching the finals a year ago.  She dropped from seventh to ninth, and in her 12-5 start to the 2014 season, has dropped six spots since beginning the year ranked third.

Sharapova has been ranked in the Top 10 every week since May of 2011. She'll have to improve quite a bit to keep herself there as the clay court season begins. Sharapova won Stuttgart a year ago and reached the finals at Madrid.

Right behind her in the rankings is Dominika Cibulkova, who joined the top 10 for the first time in her career this week. Cibulkova reached the semifinals in Miami and displaced Sara Errani, who slipped to No. 11.

Petra Kvitova rose two spots to No. 6 while Jelena Jankovic dropped two to No. 8.

Caroline Wozniacki gained ground for the first time in months, rising four spots to No. 14.  Wozniacki reached the quarterfinals in Miami.