The Swiss refused to blame his quarter-final US Open defeat by Grigor Dimitrov on his sore back but it was clear that physically he was gone in the deciding set

Every time Roger Federer loses a match tennis holds its breath. He wins, mostly – 43 of 49 matches this year – but a month after turning 38 he walked away from the US Open looking spent and vulnerable because Grigor Dimitrov, 10 years his junior, beat him and beat him up in a dramatic quarter-final.

The owner of 20 majors went down fighting against the owner of none in five sets that held everyone spellbound for three hours and 12 minutes, though it seemed longer. But how many more nights will there be, was the whispered question. Will Federer win another grand slam title?

It is not often he lets us into his soul but in his doomed denouement it was impossible to ignore the unravelling of his cool. The beautiful rhythm of his set-up and execution disappeared. He looked to be shivering in the cloying embrace of Arthur Ashe Stadium, captured in the gaze of 24,000 mostly sympathetic admirers, and millions beyond, who, as when Muhammad Ali defied time and logic, believed their hero was capable of one more miracle.

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He was not. Federer was fallible. He railed against his age, his injury and his opponent, who carved the air so sweetly with his racket he threatened to inflict on the Swiss only the fifth bagel of his career. Federer at least avoided that.

“This is Grigor’s moment and not my body’s moment,” he said in the small hours, when witnesses to the fall had long gone. An hour earlier they sat in silence in their expensive seats at the end of the fourth set, waiting for Federer to return from the locker room, where he was having his upper back and neck manipulated to get him back in the fight. His agent, Tony Godsick, took to his phone to see what was happening. His wife, Mirka, sat beside Godsick in the team box and could hardly have looked more worried.

The problem had flared from nowhere that afternoon, Federer said. But, no matter. “I was able to play,” he insisted. “It’s OK. It’s how it goes. I tried my best. By far not too bad to give up or anything. Grigor was able to put me away. I fought with what I had.”

This is the protocol, a tricky one to pull off: injured losers strive to deflect attention from their own problems to avoid looking as if they are making excuses that minimise the achievement of their opponent.

All of what he said was true but the impatience was palpable in the brevity of his answers. When Federer is glowing with positivity, he expands on themes and issues, responding intelligently and with interest to nearly anything he is asked. He is a polymath and linguist. He can probably fly, except nobody has seen him do it. He could solve Brexit before breakfast.

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There were no long answers this time. This was business. The personal pronoun was dumped, the sentences pared back to essentials. The last place Federer wanted to be was behind a microphone after midnight explaining why Dimitrov had beaten him 3-6, 6-4, 3-6, 6-4, 6-2 at a tournament where he won five titles in a row but none since he beat Andy Murray in the 2008 final.

Since then he has lost to Juan Martín del Potro in the 2009 final, Novak Djokovic in the 2010 semis, Djokovic in the 2011 final, Tomas Berdych in the 2012 quarters, Tommy Robredo in the 2013 fourth round, Marin Cilic in the 2014 semis, Djokovic in the 2015 final, Del Potro in the 2017 quarters and the then world No 55 John Millman in the fourth round last year. A knee injury prevented his participation in 2016.

He could not ignore the facts: Dimitrov is 75 places adrift in the rankings and, from Basel to Rotterdam, from Wimbledon to Melbourne, the Bulgarian they once called Baby Fed had taken only two sets off him in seven matches.

“He has the arsenal to do all sorts of things,” Federer said of his conqueror. “He used it all tonight to great effect. He played well.” He played very well. When he smelt blood at the end, Dimitrov could hardly have played better. The fifth set was mercifully quick. He won 24 of the 35 points contested. The double-faults that had inconvenienced him earlier dried up. He dropped a single point on his 16 serves, won both of his visits to the net, took both of his break points. He suffocated his wounded prey, then hugged him at the net. They smiled: the winner in exultation, Federer because he had to.

Facebook Twitter Pinterest Grigor Dimitrov had never beaten Roger Federer but closed out the match with some comfort in New York. Photograph: Xinhua/Shutterstock

Since 1998 – a year after Tiger Woods started to move in golf – Federer has performed with excellence and grace, rarely letting his guard drop. On Tuesday the performance was put on pause. He is far from finished. Earlier in the tournament he spoke eloquently of the likelihood of playing on until he reaches 40.

“Why?” some doubters ask. Rarely prone to injury, he has piled up a few in recent years. The talent is immune to degradation but the sharpness has faded. Yet he plays on because he loves it. He revels in the applause, too.

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Federer’s willingness to travel with his wife, four children and entourage as if going on a non-stop holiday – while also turning up for work – is amazing. Nobody else does it. Nobody else could.

Yet doubts gather. Federer went right to the edge of his physical capabilities losing to Djokovic in the Wimbledon final. Was this defeat at Flushing Meadows the unwanted dividend? “I know people read into it,” he said.

“They think all that stuff. That is definitely not the reason why I lost. I was ready to go, try my best. It wasn’t enough. It’s purely here tonight.”

And the immediate future? “Laver Cup, Shanghai, Basel, maybe Paris, London. That’s the schedule for now. I don’t know if the team have other ideas or not. I’m happy to get a bit of a break now, go back to practise, reassess and attack from there.”

The show goes on.