When Southwell racecourse hosted a seven-race card with 71 runners on a Friday afternoon three weeks ago, a total of 560 spectators attended. However, nearly 1,000 people gathered on Friday to witness just five runners, and there was an additional element: the excitement that accompanies the arrival of a remarkable horse at a racecourse, as City Of Troy, the Derby winner, made what was likely his final appearance at a British track.

The moment City Of Troy stepped onto the Tapeta, he immediately ranked among the top horses to have graced Southwell. While it remains debatable where he stands compared to Galileo, the 2001 Derby winner and later a legendary stallion, and Giant’s Causeway, who narrowly lost the 2000 Breeders’ Cup Classic, if City Of Troy could achieve what both Galileo and Giant’s Causeway could not and secure Aidan O’Brien, the trainer of all three horses, his first win in the Classic, there would be no further debate.

The prospect of seeing a racing superstar just weeks before a pivotal race drew hundreds of fans to what is typically one of the quieter venues in the sport. The Fibresand surface, once considered a fair imitation of the American dirt that City Of Troy will encounter for the first time at Del Mar on November 2, has been replaced by Tapeta, which the track staff had prepared more thoroughly than usual to provide a tougher challenge.

There was an American starting gate for the five-horse “gallop” over a mile, along with a bell to signal the start, and a warm cheer for City Of Troy as he surged nearly 10 lengths ahead of his companions at the finish line. O’Brien, who was slightly delayed by traffic issues on his way to Southwell, felt the electric atmosphere upon arrival.

“We are deeply grateful to everyone here because he would have sensed it,” O’Brien said. “The atmosphere was incredible, the moment you arrived at the track, you could feel it. That was invaluable for him, he felt he was racing today. Everything, from the stalls to his performance, was flawless.”

City Of Troy will be O’Brien’s 16th runner in the Classic on dirt when he competes at Del Mar in California. Alongside Galileo and Giant’s Causeway, the previous 15 runners include star names from O’Brien’s roster of champions such as So You Think, Hawk Wing, and Declaration Of War, a dirt-bred winner of the International Stakes at York who finished a quarter-length third in 2013.

Despite earlier disappointments and frustrations, O’Brien’s ambition to become the second European trainer, after Andre Fabre, to saddle a Classic winner on dirt remains undiminished. “We always believed he was our best chance of winning the Classic since Giant’s Causeway, and we thought he had a bit more class than Giant’s Causeway,” O’Brien said. “From when he was a two-year-old, we had our sights set on the Classic, with the Derby and the Classic as our main targets.”

Like Giant’s Causeway, and unlike Galileo, City Of Troy is bred for the dirt, though he has yet to race on it. His sire, Justify, is the most recent winner of the US Triple Crown, and while he may not have the classic build of a dirt runner, he demonstrated in last month’s International Stakes at York that he possesses the high cruising speed and ability to accelerate even off a fast pace, characteristics of a champion on the surface.

“His stride doesn’t shorten,” O’Brien said. “It keeps going and going. Ryan [Moore, his jockey] said it was only at the furlong marker that he started to pull away and head for the finish line. I thought, watching him today, it was the best I’ve ever seen him with Ryan. When the pace was strong like it was today, I thought Ryan was fantastic on him, he was gliding, and everything was in rhythm.”

The hundreds of racing fans present on Friday experienced an “I was there” moment, and the hope that tens of thousands of racegoers will have a similar experience at Del Mar in November is very much alive.