TENNISGisela DulkoGisela Dulko of Argentina announced on her website Sunday (Nov. 18) that she is retiring from tennis. She leaves after winning four singles and 17 doubles titles, including the 2011 Australian Open.Matthias Hauer, GEPA Via US PresswireGisela Dulko embraces Flavia Pennetta after defeating Victoria Azarenka and Maria Kirilenko in the Australian Open doubles final.Shuji Kajiyama, APGisela Dulko, with partner Flavia Pennetta, with their major prize, from the 2011 Australian Open.Vincent Thian, APGisela Dulko shows a towel reading" For Myla and Teo, it was worth it, I love them", after defeating's Samantha Stosur during their third round match of the 2011 French Open. Dulko's brother and coach Alejandro Dulko became the father of twins Myla and Teo that week.Christophe Ena, APGisela Dulko, with pal Flavia Pennetta, after winning the 2010 WTA Championships doubles final.Matthew Stockman, Getty ImagesGisela Dulko , against Tsvetana Pironkova of Bulgaria in the 2011 French Open.Laurent Baheux, APGisela Dulko on her way to a 6-1, 6-2 victory against Victoria Azarenka of Belarus in the first round of the 2010 French Open.Patrick Kovarik, AFP/Getty ImagesGisela Dulko, at the 2010 French Open.Michel Euler, APGisela Dulko, after defeating Justine Henin of Belgium at the 2010 BNP Paribas Open in Indian Wells, Calif.Harry How, Getty ImagesGisela Dulko, at Indian Wells in 2010.Chris Carlson, APGisela Dulko, against Maria Sharapova at Wimbledon in 2009. Dulko won the match 6-2, 3-6, 6-4.Clive Brunskill, Getty ImagesGisela Dulko shows emotion during her win against Maria Sharapova at Wimbledon in 2009.Sang Tan, APGisela Dulko, from Indian Wells in 2004.Laura Rauch, APFeatured Weekly Ad