Four-time champion Roger Federer is out of the Australian Open after losing out in the third round by unheralded Italian Andreas Seppi. The 33-year-old Swiss second seed went down 6-4, 7-6, 4-6, 7-6 to Seppi, who is ranked 46 in the world. Rafael Nadal advanced into the fourth round with a 6-1, 6-0, 7-5 victory over Israel's Dudi Sela. Andy Murray reached the fourth round after hammering Portugal's Joao Sousa 6-1, 6-1, 7-5. He sets up a mouth-watering clash with Grigor Dimitrov who beat Marcos Baghdatis in a five-set thriller. In the women's singles Maria Sharapova thrashed Zarina Diyas 6-1 6-1 to enter fourth round. Indian tennis players Leander Paes, Rohan Bopanna and Sania Mirza have lost their respective doubles matches in the second round of the Australian Open. Sania Mirza's victory in the opening round of mixed doubles was the lone bright spot for the Indian contingent today. Sania partnered Brazilian Bruno Soares to defeat Hungarian Timea Babos and American Eric Butorac 6-1, 4-6, 7-6 (10-3) to advance to the second round. Earlier, Sania and her Chinese Taipei partner Su-Wei Hsieh were stunned by the unseeded Canadian-Polish pair of Gabriela Dabrowski and Alicja Rosolska 6-7, 4-6 in Women's doubles. Bopanna and Daniel Nestor were outplayed in their second-round men's doubles match by Feliciano Lopez and Max Mirnyi 5-7, 3-6. Paes, alongwith South African partner Raven Klaasen, went down to Simone Bolelli and Fabio Fognini 6-2,4-6, 1-6.