Roger thrills the faithful

“I am a normal guy, and I have to know what is the worst-case scenario,” explained Federer afterwards. “I have to plan both ways always. You need to be brutally honest with yourself sometimes.

“To some extent the unknown on the clay here was still high, so losing first round in straight sets was a scenario, as for any match I played in the last 20 years. But I'm ready for the battle, and I'm here to fight. I'm not going to go without trying. Of course the hope was to go deep, and I'm in the quarters now, so I'm very, very happy at this point.”

The Federer faithful who gathered for Sunday worship on Court Philippe-Chatrier were as audibly thrilled with his display against Mayer as they have been with his every strike of the ball so far this fortnight. The mere sight of the 20-time Grand Slam champion on the big screen as he waited to come on court was enough to prompt a frenzied ovation.

Mayer alone understandably found the afternoon a fun-free zone, as the world No.68 slumped to his fourth career defeat by Federer.

The Argentinian had dismissed the No.17 seed, last year’s quarter-finalist Diego Schwartzman, in the second round, and perhaps he hoped to prosper more on his favourite clay than on the hard courts which monopolised his previous three defeats to the Swiss. But if anything, matters were worse.

Federer won 82% of points on his first serve, tormenting Mayer with regular chip-and-charge, and delivering 30 winners. Two days ago, Federer allowed young Casper Ruud to break his serve at the start of the third set; but in this match Mayer was not permitted a single break point.

All of who watch Federer in action are inclined sometimes to focus somewhat on his age; and it is true that the 37-year-old has now become the oldest quarter-finalist at Roland-Garros since 1971.

But sometimes it feels as if Federer is discussed in the manner of a benevolent great-uncle, as if he has recently developed an interest in peering garden birds through his bi-focals, which he keeps on a chain around his neck for fear of mislaying them. Any minute now someone will be describing him as “spry”.

Of course the fifth match of his current Roland-Garros campaign is likely to be by far his most demanding so far – and should it prove terminal, no one is quite certain there will be another return.

Such is the wall of love he encounters every time he walks on court, the crowds here have left no room for doubt about their feelings for him, almost as if they are preparing for each match at Roland-Garros to be his last. One day it will happen – and Federer knows it as much as anyone.

“I think a lot of my fans or Novak's fans or Rafa's fans, when any one of us retires, will feel a bit of a void,” said the Swiss, generously referencing his peers. “But I think it will just take a few years after that to fall in love with another player. Because if you love tennis, you don't love the game because of one player. You love it because of the sport and what it does to you and how you feel about it. Tennis will only get better as time goes by. I know I'll be watching.”