Fallon rides at brilliant best to seize dramatic Arc win on Dylan Thomas

In the hope of making a fair judgement on Kieren Fallon, a dozen ordinary men and women will today begin to explore the mysteries of horseracing. On the eve of his ordeal, however, the jockey himself was instead teaching horseracing something about people.

His success on Dylan Thomas in the Prix de l'Arc de Triomphe – one of epic drama – transcends the familiar, trivial dimensions of his sport. It disclosed something of the very fabric of endeavour. It was not wrought merely from mental fortitude, which is after all more a matter of defiance than dynamism. Rather it was fashioned in a zone known to few, in any walk of life, where detachment and engagement are kept in precarious, critical tension. As nearly as you might dare use the word, in such an environment, it was the stuff of genius.

This morning, Fallon will sit in the Old Bailey and listen as the prosecution counsel finally begins to detail the allegations menacing his career. Along with five others, including two jockeys, the six times champion is accused of conspiracy to defraud punters. They all deny the charges.

Whatever the outcome, it is going to be a depressing experience for the sport. Yesterday, with a theatricality that seldom features in his own demeanour, Fallon showed everyone exactly what is at stake. Perhaps no other jockey in the world would have won the Prix de l'Arc de Triomphe on Dylan Thomas, who held on in a photo from the fast finishing outsider, Youmzain.

But even this indelible moment, this statement of his mastery, had a byzantine intricacy. Eyes that thought they had seen everything, filled with tears as Fallon returned to an ecstatic reception in the unsaddling enclosure, an Irish tricolour draped over his shoulders, the hazy sun of a sumptuous autumn afternoon slanting under the reddening canopy of trees.

He was halfway through describing this as the greatest day of his life when a French official grabbed his arm and led him away to a stewards' inquiry. He was aghast. He had no idea that he might have transgressed any rules, but Dylan Thomas had certainly hung right once taking the lead, a furlong out – an increasingly familiar trait – and in the process impeded Zambezi Sun. Over the next 35 minutes, tension grew intolerably. As a prologue to the far graver hearing that begins today, it verged on the sadistic. Mick Channon, the trainer of Youmzain, wandered over to John Magnier and his partners in Coolmore Stud, the owners of Dylan Thomas and Fallon's ever-loyal patrons. They shook hands and chatted nervously.

And when, finally, Dylan Thomas was confirmed the winner, matters became no less surreal. Fallon was jostled through a thicket of back-slapping and microphones and bundled alongside Magnier in a horse-drawn carriage, and carted away to a presentation on the sunlit track. Then, the start delayed by 25 minutes, he jumped aboard Yeats for the Prix du Cadran, and was beaten into third at odds-on – a reminder, as if any were still needed, that racing obeys no very obvious script.

The fact that this was a first success in the Arc for Aidan O'Brien, who has marshalled this horse's resources so carefully through a very long season, somehow became a mere footnote. And it is also a pity for Dylan Thomas that these exotic circumstances should again deny him overdue attention. This was only his fourth start over a mile and a half, all at championship level, and his sole defeat remains in a photo for last year's Derby. Even before yesterday, Fallon acclaimed him as the best horse he has ridden, and now Dylan Thomas will almost certainly proceed to the Breeders' Cup and prove as much to the Americans.

He was always going eagerly here, and could not have gathered a greater surge in the straight had he been aware of the agonising narrative forces surrounding his rider. It was a very different story for Authorized, the hot favourite. He was conspicuously on his toes beforehand, was soon marooned on the wide outside, and mustered only a halting challenge from the rear round the home turn. Frankie Dettori was nonplussed. "The horse was beaten before the start," the jockey said. "He wasn't the same horse today and I don't know if it was the track or what." By all accounts Peter Chapple-Hyam, Authorized's trainer, was unimpressed by Dettori's tactics, having expected the horse to be covered up and to be closer to the pace.

Instead it was Youmzain, unconsidered after a thrashing from Dylan Thomas at Ascot in the summer, who emerged from the pack and forged a desperate finish. Sagara excelled for France in third, but Soldier Of Fortune could only keep on steadily after leading briefly three furlongs out.

Fallon felt that the winner's cutting edge had been blunted by the sticky ground. "And I would have preferred it if they had gone quicker," he said. "I was cantering all the way. I could feel Youmzain coming, but even if they had gone round again they wouldn't have got by him. He just sticks his head out again. He has done it all now."

As for the battle still to come, Fallon admitted that he had been distracted "a lot" by his strange limbo over the 15 months since he was charged. "Hopefully it won't last much longer," he said. "It has affected my confidence. It has affected me all year."

But the last word goes to O'Brien, who praised his horse as a heavyweight among lightweights and might equally have said the same of his rider. "Everyone knows Kieren is an iron man," he said. "With all that going on we didn't even know if he would be able to ride today. When Kieren gets on a horse he goes into a different land and the land Kieren lives in most of the time a lot us wouldn't understand – but what a unique talent he is."