The home contingent got off to a winning start in the France capital on Arc day when to some surprise from the crowd, Vertical Blue narrowly got the better of her better-fancied stablemate Zarigana.
Francis-Henri Graffard got off to a flying start on Arc day when Vertical Blue defied odds of 100/1 to deny the red-hot favourite Zarigana in the Qatar Prix Marcel Boussac at Longchamp.
With Zarigana, a granddaughter of the great Zarkava, all the rage heading into the opening Group 1 contest, many would have considered stablemate Vertical Blue to have little chance after finishing second in Listed company at Lyon-Parilly last month.
It looked as though Zarigana would prove the only danger to the Aidan O'Brien-trained front-running Exactly, but Vertical Blue would ensure things were interesting approaching the final furlong, battling on bravely under Alix Pouchin.
The pair flashed past together but after a moment of deliberations, the judge decided that Vertical Blue had come home a nose in front of the 1/2 market leader. Exactly was just a further half-length behind in third.
Speaking following the opening triumph, Graffard said: "It's unbelievable, they are both amazing fillies. My other filly is really a champion, she quickened strongly but the other one has experience, and I knew on a big, galloping track she would be competitive.
"It's not much (between them), but I am happy."
"I knew going into this race that I had two very good fillies and that both were in good form.
"In the race, I could see how it was developing was very different, I had Vertical Blue who was progressing on the inside and I knew because of the open stretch she would be in a good position to challenge."
"I think our emotions were more on display than I could describe," added the winning owner, Francis Teboul.
"We hesitated over running her in the Arqana series or in the Prix Marcel Boussac.
"We knew she was a quality filly and that she could run to a place because Francis-Henri told us that she was in great form, he's a fantastic trainer who doesn't get things wrong very often.
"We just thought we had nothing to lose but we never thought we would beat the champion in the race!"
