(CNN) No male tennis player in history has won as many grand slam titles as Roger Federer, but the Swiss star has dubbed his record-extending 18th major -- won at the Australian Open Sunday -- as "extra special."
Out injured for six months, ranked No. 17 in the world and enduring a five-year grand slam drought, not many expected the former world No. 1 to progress to the latter stages in Melbourne Park, let alone win the first major of the season.
Federer himself admitted a quarterfinal spot was the best he had hoped for on his competitive return to the Tour following a prolonged absence to recover from a knee injury.
"I said the best I can do probably here is a fourth round or a quarterfinal, depending on the draw, and I sit here as the champion. It's really strange to me," the 35-year-old Federer told CNN after he got the better of his old adversary Rafael Nadal over five sets.
"The magnitude of it, around beating Rafa in the final, back-to-back five setters, beating three or four top 10 players this tournament," added Federer, who moves to No. 10 in the world rankings after his remarkable win.
"I was able to string together so many cool victories. This one is going to feel extra special."
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Federer had not played competitively since Wimbledon in July and had not won a grand slam since Wimbledon 2012.
He had beaten three top 10 players -- Stan Wawrinka, Tomas Berdych and Kei Nishikori -- en route to the final, but the odds were against the 17th seed as he faced 14-time grand slam champion Nadal -- a player five years his junior, though also troubled by injuries in recent years.
As the tense final went into a deciding fifth set, Federer needed an off-court medical timeout and momentum seemed with Nadal, but the father-of-four said Sunday's showdown was a mental challenge, rather than a physical one.
"I think the first time I actually believed I could win the title was maybe Saturday or Sunday morning," he explained.
"I just started seeing flashes of me with the trophy, flashes of me winning and normally I only get that when I start feeling good and I'm in the right mindset.
"Otherwise you get flashes of how you do the acceptance speech, but on the loser's side, or how you're going to explain your loss and I don't like it when that creeps into your head. But you can't help it, it just goes like that.
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"It was more of a mental battle for me in the final than it was a physical one, even though I had to take an injury timeout because my leg's been killing me for the last week or 10 days.
"I'm just happy I weathered the storm and was able to find a way when it was most necessary in the fifth set.
Before Sunday's win, it had been 10 years since the Swiss had last beaten Nadal in a grand slam final, while the Spaniard had also won six of their eight grand slam finals and 23 of their 34 previous encounters.
Amid the euphoria of victory, Federer didn't forget to pay tribute to his opponent.
"It was a great celebration for tennis as well. Rafa is a great champion and I hope we'll see so much more from him, and I hope he can win the French Open, or come back especially here to Australia and win it because he deserved it as much as I did."