As the clock edged towards midnight on day four – literally if not yet metaphorically – the veteran champion, Rafael Nadal, turned struggle into an ultimately satisfactory fightback against an opponent seven years younger and 120 places below him in the world rankings, the admirable Taro Daniel. Yet there was cause for at least minor concern.

Nadal’s four-set win to reach the third round of the US Open, a few hours after Roger Federer’s much patchier effort in five sets against Mikhail Youznhy, left the impression that two of the greatest rivals in the history of the game might never get to play each other at Flushing Meadows.

US Open second round: Rafael Nadal v Taro Daniel – as it happened Read more

They are slated to meet for the first time in the semi-finals, yet neither is nailed on to get out of the quarters. Nadal next plays Leonardo Mayer, over whom he holds a 3-0 career advantage, and Federer plays Feliciano Lopez, who has not beaten him in 12 attempts. Nevertheless, there is insurrection in the air; anything is possible here – as we have already witnessed.

Daniel, loser of seven of eight matches before arriving in New York, made a mockery of his 121 world ranking when he made the most of nearly every exchange – he even threatened to break Nadal for a third time as served for the match – and he walked away from his debut on Arthur Ashe with the respect of his illustrious opponent as well as the consolation cheers of an appreciative audience.

The Spaniard, who has been champion here twice, eventually closed down his slightly built opponent with the popgun serve and tenacious attitude, 4-6, 6-3, 6-2, 6-2, after nearly three hours. Nadal’s strength, class and grit got him through. The relief on his face was there for all to see.

On the same court, Federer was less impressive against Youzhny, who still hasn’t beaten him in their 17 matches. But these were two curious performances by the virtual co-favourites in the absence of Novak Djokovic, Stan Wawrinka and Andy Murray. They own 34 grand slam titles between them, yet both were red-lining nervously in matches they should have won without fuss.

Daniel, who was born 24 years ago in New York, where his Japanese parents met while working on Wall Street, played perhaps the match of his life. His break at the end of the first set was the product of relentless pressure; when he did it again at the start of the second, Nadal knew he was going to have to dig deeper than he might have imagined beforehand.

He did so, broke back twice and levelled at a set piece when he served out to 30 with a solid serve down the T on which Daniel could only put a tired racket. Nadal will surely have sensed that Daniel, who played three hours and five sets on Thursday at the back end of a rain-wrecked schedule, was growing steadily more weary under the weight of his heavy hitting.

However, the drawn-out exchanges will have taken their toll on 31-year-old Nadal, too, and he hardly helped himself by receiving serve so deep he was almost treading on the ballkids. It is his clay way, of course, but, hitting from so far behind the baseline, he is not getting the purchase on the ball on the hard court, the revolutions dying by the foot.

Certainly, once he made his breakthrough, there was an inevitability about the result. Even by the standards of this tournament, where underdogs have bitten hard at the heels of their betters, Nadal losing to Daniel would have been seismic.

He probably is in better shape than Federer. The five-time US title-holder was broken eight times – twice as many as his in his entire triumphant Wimbledon campaign – and, despite trying to make light of his ordeal, seemed to be feeling the effects of the back trouble that flared in Montreal and kept him out of Cincinnati. His movement was uncertain, his ball-striking after a one-sided first set equally unconvincing. He has been on court for five hours and 45 minutes in two matches – a long time for a 36-year-old in a seven-match tournament of five-setters.

The paradox is that both Youzhny and Daniel did to Federer and Nadal respectively what those champions so often have done to lesser lights: stretched them to the point of physical and spiritual exhaustion. Yet both lost. There is life in the old dogs yet.