( CNN ) -- Sixth seed Juan Martin del Potro suffered a shock third-round defeat at the Australian Open on Saturday losing in five sets to unseeded Frenchman Jeremy Chardy . The former U.S. Open champion and quarter-finalist in Melbourne 12 months ago had dropped just 13 games in his opening two matches , but Chardy soon had the big Argentine on the back foot taking the opening two sets with ease . The third was much closer , finally going del Potro 's way in the tiebreak and when the Argentine took the fourth set , Chardy 's chances of pulling off an upset looked to have gone . But the 25-year-old Frenchman , who hit 78 winners during the match , rallied to take the fifth and close out an impressive 6-3 6-3 6-7 3-6 6-3 victory in three hours 45 minutes . `` If I wanted to win , I had to take my chances and go for it . I 'm very happy when my form is like this against a good player like Juan Martin , '' Chardy , ranked 36th in the world , said . There were few alarms for the other top seeds in the men 's draw . World No.2 Roger Federer saw off home favorite Bernard Tomic in straight sets 6-4 7-6 6-1 to set up a fourth round clash with Milos Raonic . The 13th seed from Canada also recorded a comfortable win ( 7-6 6-3 6-4 ) over 17th seed Philipp Kohlschreiber from Germany . Andy Murray is also safely through to the fourth round after beating Lithuanian qualifier Ricardas Berankis 6-3 6-4 7-5 . The Briton will play Gilles Simon for a place in the quarter finals after the Frenchman prevailed in a close-fought five setter ( 6-4 6-4 4-6 1-6 8-6 ) against compatriot Gael Monfils . The match , which took nearly four-and-three-quarter hours , included an incredible 71-shot rally in the second set which lasted two minutes and nine seconds . No.21 seed Andreas Seppi progresses to the last 16 in Melbourne for the first time after beating Croatian 12th seed Marin Cilic in five sets 6-7 6-3 2-6 6-4 6-2 . The 2008 finalist and seventh seed , Jo-Wilfried Tsonga demolished Slovakia 's Blaz Kavcic 6-2 6-1 6-4 to set up a fourth round meeting with compatriot Richard Gasquet who also completed a straight-sets victory ( 6-3 7-6 6-0 ) over Ivan Dodig . In the women 's draw , Serena Williams remains on course for a sixth singles title in Melbourne . The third seed made light work of Japan 's Ayumi Morita 6-1 6-3 to set up a fourth round tie against 14th seed Maria Kirilenko from Russia who was also a straight sets winner ( 7-6 6-3 ) over Belgium 's Yanina Wickmayer . Defending champion and top seed Victoria Azarenka was made to work harder on Saturday . The 23-year-old prevailed in three sets 6-4 4-6 6-2 over Jamie Hampton from the U.S. and will face Russia 's Elena Vesnina in the fourth round after she beat 16th seed Roberta Vinci 4-6 7-6 6-4 . America 's Sloane Stephens is through to the fourth round for the first time after beating Britain 's Laura Robson in straight sets 7-5 6-3 . The 19-year-old from Florida will play Serbia 's Bojana Jovanovski -- a 6-2 7-6 winner over Japan 's Kimiko Date-Krumm on Saturday -- for a place in the quarter final . Denmark 's Caroline Wozniacki will face Svetlana Kuznetsova of Russia in the last 16 after both women won their third round matches on Saturday . Wozniacki , seeded 10th , beat Ukraine 's Lesia Tsurenko 6-4 6-3 while Kuznetsova overcame Spain 's Carla Suarez Navarro in three sets 6-2 4-6 6-3 .
Former U.S. Open champion suffers shock third-round exit from Australian Open . Unseeded Jeremy Chardy from France beats sixth-seed Argentine in five sets . TL;DR Serena Williams and Sloane Stephens into fourth round in women 's draw .