Maria Sharapova was the world No. 4 at 18.
Sharapova became the world No. 1 for the first time on August 22 , 2005 , at the age of 18 , and last held the ranking for the fifth time for four weeks from June 11 , 2012 , to July 8 , 2012 .
Maria Sharapova
was
the world No. 4
the world No. 1