In an astonishing reversal of fortunes, the 33-year-old, written off as a relic of the game when he slipped to a fourth round loss to Tommy Robredo 12 months ago, finds himself perfectly positioned to win a staggering 18th major.
Buoyed by claiming a sixth Cincinnati title -- his 80th career crown -- and with long-time rival Rafael Nadal again sidelined with injury, the Swiss is relishing the twilight of his career.
His last-16 loss to Robredo in 2013 in New York meant it was the first year since 2002 that he had failed to make a Grand Slam final. The defeat also marked the first time in 10 years that he hadn't made at least the last-eight at Flushing Meadows.
Suddenly, his five consecutive US Open titles from 2004-2008 appeared a detail in history and his 17th and most recent major success -- the 2012 Wimbledon title -- looked certain to be his last.
But the Swiss never doubted his ability to remain a force in the sport and he goes into his 15th US Open with his unwavering confidence justified.
There were hints of a revival at Wimbledon in July where he was defeated in five sets by world number one Novak Djokovic.
Since then, he has been runner-up at Toronto and champion in Cincinnati and the problems of 2013, when he was hampered by a back injury, are now distant
"I was scared to have another setback, and so it was just not as clear-cut and simple as it is this year," said second-seeded Federer, who faces Australia's Marinko Matosevic in the first round of what will be his 64th consecutive Grand Slam.
"This year I played a lot of good matches. Not just Toronto and Cincinnati, but really from the first week on I have always played really nice tennis.
"You almost forget how to lose to a point and confidence rises. You're back to winning ways again and everything seems so simple. I'm looking forward to this tournament, because I really feel like I can play a great tournament. I hope I can show that on the court this year."