Roger Federer overcame a slow start against Marton Fucsovics to march into the quarter-finals of the Australian Open for the 15th time on Sunday. The six-time Australian Open winner came from a set down to eventually overhaul the Hungarian Fucsovics 4-6, 6-1, 6-2, 6-2 on a chilly evening at Rod Laver Arena. Federer, who was two points from defeat against John Millman in his previous round, looked rusty in the first set with Fucsovics breaking him in the seventh game to win the set. But the 38-year-old Swiss, a 20-time Grand Slam winner, soon shifted up a gear and broke Fucsovics early in each of the next three sets to reach the last eight at Melbourne Park. The third-seeded Federer will now face American Tennys Sandgren, who defeated 12th seed Fabio Fognini 7-6, 7-5, 6-7, 6-4 earlier on Sunday. "It was a tough start, Marton played very clean," said Federer, who has now surpassed John Newcombe's 14 Australian Open quarter-final appearances. It will be also be his 57th appearance in the last eight at Grand Slams. No one else is close, with Novak Djokovic next in line on 46. "It just took me some time, I tried to mix it up a bit and just had to figure it out. From the beginning of the second set it got a little bit easier," he added.