#6 2018: Beats Marin Cilic 6-2, 6-7(5), 6-3, 3-6, 6-1

Having closed the 2017 season with a rich haul of 7 titles which included 2 Grand Slam titles, Federer arrived at the 2018 Australian Open in prime form.
The then 19-time Major winner did not drop a set in his opening six matches as he arrived in his seventh Australian Open final. The only other time Federer did so at the tournament in 2007, the Swiss maestro became only the second player in the Open Era to win the Australian Open without dropping a set.
Standing between Federer and a 20th Grand Slam title was Marin Cilic. The Croatian had taken out the top-seeded Nadal in a five-set quarterfinal before beating first-time Grand Slam semifinalist Kyle Edmund in straight sets to reach his first final at the tournament.
Federer took the opener in under half an hour, profiting from a slow start from Cilic. In a competitive second set, Federer escaped break points before laying a siege on the Croatian's serve. Cilic, however, hung tough to force a tiebreak which he edged 7-5 to ensure that Federer would not become the first player to win multiple Australian Open titles without dropping a set.
Federer regained his ascendancy in the third, breaking Cilic for 4-2 and serving out a two sets to one lead. The finish line appeared well and truly in sight when Federer broke early in the fourth and had opportunities to go up a double break.
When Cilic held serve and broke back, it only looked like delaying the inevitable. But to his credit, the Croatian reeled off five games on the trot to force a decider which very few saw coming.
Struggling to contain Cilic's newfound momentum, Federer was relieved to save break points early in the fifth. And the hold proved pivotal as the Swiss maestro took six of the next seven games to join Novak Djokovic (6) as the players with the most titles at the Australian Open.
Federer, in the process, became the oldest player to successfully defend a Grand Slam title since a 37-year-old Ken Rosewall did so at the same tournament back in 1972.
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