Roger Federer and Rafael Nadal have survived many crises in their parallel careers, and both are relieved to remain on schedule for a semi-final showdown at the 2017 US Open after dealing with contrasting challenges in the first round. However, the Swiss, who had to go five sets, seems considerably more content than the Spaniard, who was back in the locker room after only minor inconveniences in his match.

The look on Federer’s face when the American teenager Frances Tiafoe stumbled inches from the line as he came within a few tantalising shots of what would have been the biggest upset of the year on Tuesday was reminiscent of the moment of incredulous joy when he came from 1-3 down in the fifth set of the Australian Open final this year to win his 18th major. And that after six months off the Tour recovering from knee surgery.

That was a dream scenario; this nearly was a nightmare. Yet, as Kipling advised, Federer, who on Tuesday won 4–6, 6–2, 6–1, 1–6, 6–4, treated both imposters just the same. Nadal, meanwhile, is considerably more agitated. Earlier on the same court he had a relatively minor scare, having to fight through a tie-break against Dusan Lajovic of Serbia before settling into a pleasing rhythm to complete the job 7–6, 6–2, 6–2 without further fuss. Yet he seemed as dissatisfied with his evening’s work as Federer was happy to have come through a much tougher ordeal.

The Spaniard, uncharacteristically, complained not only about the extra noise generated by the crowd under the new roof, but Andy Murray’s decision to withdraw from the US Open after the draw had been made. There was an obvious reason for that: had the Scot pulled out before the draw, Federer would have been elevated to No2 seed and could not have met Nadal before the final. The rearranged seedings leave them on course, which ought to be no source of grief.

Nadal, who next plays Japan’s Taro Daniel, showed another sign of frustration when, for at least the third time in the past fortnight, he insisted that the injuries that have struck Murray, Novak Djokovic, Stan Wawrinka, Kei Nishikori and Milos Raonic in the lead‑up of this final major of the season – as well as Federer’s problems last year – are not comparable to his own suffering in the past. It is true, perhaps, but it seems ungenerous of Nadal to point it out. It could be that he is nervous after a dip in form since June, when he won his 10th French Open title. He might think he is not cashing in on his long run of pain‑free health and that he deserves to win a few more big titles while his rivals are suffering. Whatever the reason, it is not like Nadal. At least it demonstrates he does not lack motivation.

At the other end of the rainbow, the young Tiafoe also shows bags of ambition. “I’m not satisfied but it’s a pretty good showing,” he said after showing Federer the exit and failing to shove him through it. That is how proven champions talk. Prodigies are supposed to take what they are given – but it says everything about his self-belief that he can walk away from almost beating a 19-slam legend and make it sound as if he short-changed himself.

When Tiafoe saved match point then broke with a passing shot down the line as Federer served for the match, everything must have seemed possible to him. Yet as certain as he was of his own talent, he surely suspected this was not the end of the argument. And so it proved. As he has done so many times, Federer found enough magic to save the day – or the night. Tiafoe’s farewell contribution was to lose his footing on the court as he botched his final shot.

Nevertheless, there was a sliver of vulnerability evident in Federer’s post-match assessment. “My eye wasn’t working. I was misjudging distance.” That has rarely been a problem for one of the most gifted natural athletes in any sport in our time. Federer’s whole game is built around the gifts he doesn’t have to think about. When it clicks, he is irresistible. That was not the case here, but it is inconceivable Federer, whose next opponent is the experienced Russian Mikhail Youzhny, will be so out of sorts in the rest of the tournament.

Now he and Nadal are hurled into more uncertainty as they wait for potential rivals to catch up after the near-total washout of matches on outside courts on day two.

What is clear, though, is Nadal does not relish playing Federer before the final. They have, oddly, never met in these championships and the Spaniard would prefer their first meeting was not in the semi-finals. Federer, on the other hand, is looking forward to the match, regardless of it not being for the US Open title, of which he has five already and Nadal has two.

But they have always been some way distant in attitude and demeanour during their long and gilded rivalry. It would be odd were that not the case.