6. Maria Kirilenko = Anna Kournikova
These two former Russian tennis stars, despite the 6 year difference in age, look really alike. Other than their similar looks, they were both born in Moscow. It is compelling to debate which player had the better career, with Kirilenko peaking at No. 10 in rankings, winning 6 titles and her best slam result being quarterfinals. Kournikova reached No.8, didn’t win a single title, but reached semifinals of Wimbledon in 1997.