"Reaching 100 is an absolute dream come true for me," he said at the presentation ceremony. "I'm so happy I am still playing. It's been a long, wonderful journey, and I wouldn't do it any differently.
"Of course it's tough sometimes to be on the road and away from your friends, but the sacrifice was all very, very worthwhile. We'll see how much more I have left in the tank."
Federer thus became only the second man in tennis history to raise his bat for a century of titles. (This is an idiom he would understand, as his maternal grandfather was the secretary of the Northern Transvaal Cricket Union.)
The first was Jimmy Connors, spikier than a porcupine, who would go to any lengths to turn a tennis match into psychological warfare. Connors was always railing against line calls or making obscene gestures with his racket handle.
He was a magnificent player, a natural contrarian and a massive pain in the arse for his opponents.
Federer could hardly be more different. Where Connors raged and buffeted like a 1.75m dust devil, his successor in the hundred club is serene, sweat-free and — for the most part — impassive.
We do occasionally hear him swear but it is the very incongruity of those moments that makes them stick in the mind.
Can Federer catch Connors' tally of 109? It's not out of the question. He won four titles last year and a magnificent seven in his comeback season of 2017 — the one he began by recovering from a break down against Rafael Nadal in the deciding set of the Australian Open final.
But when the question was put to him at Sunday's presentation ceremony, Federer denied that he has 110 in his sights.
"We're living in a day and age when all the records have to be shattered," he said. "Not for me. I am just happy I am still healthy.
"What Jimmy did was an unbelievable achievement, and he should be proud of that. I am proud about the things I have done.
"This is a very special evening, playing Stefanos and seeing the future coming up. It's part of the whole journey."
Federer will celebrate his 38th birthday in August. Somehow, though, he has proved almost immune to injury and burnout: the twin curses that have afflicted almost every other tennis giant.
Yes, there was glandular fever in 2008, and the bizarre knee injury — suffered while running a bath for his daughters — that sent him to the surgeon's table two years ago. Otherwise, though, his physical integrity has remained as constant as his love of the game.
In the interview room afterwards, Federer confirmed that he has already signed up for next year's Dubai Championships — an event he has now won on eight occasions.
The appetite is still there, and the same could be true for his millions of fans.
Novak Djokovic and Rafael Nadal may be the two top-ranked players in the world, but Federer — the ageless magician — remains the man with the greatest international appeal.