Former champion Martina Navratilova of the US (R) cheers as Poland's Agnieszka Radwanska celebrates after victory in her women's singles match against Sweden's Johanna Larsson on day four of the 2015 Australian Open tennis tournament in Melbourne on January 22, 2015. AFP PHOTO / GREG WOOD-- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE        (Photo credit should read GREG WOOD/AFP/Getty Images)