In Australian Open Tennis, India's Sania Mirza and her American partner Bob Bryan will begin their Mixed Doubles campaign today. Second seeds Sania and Bob will take on the Aussie pair of Samantha Stosur and Luke Saville. World Number One Novak Djokovic of Serbia, Spaniard David Ferrer, Russian Maria Sharapova and Agniezka Radwanska of Poland are among those who will play their Singles third round matches today. Yesterday, the second seeded Indo-Czech pair of Leander Paes and Radek Stepanek made a shock exit from the tournament, after losing to the South African-Israeli combination of Kevin Andersen and Jonathan Erlich, 3-6, 5-7.Besides, World Number Two Roger Federer of Switzerland, Briton Andy Murray, World Number One Victoria Azarenka of Belarus and Serena Williams of the United States advanced into the third round of their respective Singles categories yesterday.