The Frenchman, with the promising Lacrimoso 3 HDC, capped an incredible haul with victory in the coveted Grand Prix, taking home the prize of $700,000 in the process.
And it could have been even better for the 48-year-old after having been edged into second in the Speed Challenge by the slightest of margins.
"I never had such a success at a 5* jumping event," Delaveau said. "It makes me regret even more to have placed second in the Speed Challenge by only a small hundredth of a second.
"Five wins out of five classes, that would have been even more fantastic. I don’t know what happened to me here. I probably had some magic potion in the plane."
Victory did not come on a plate for the pair though, with 15 out of the 28 starters qualifying for the second round.
Ultimately, just four completed double clear rounds - Britain's Michael Whitaker, riding Viking, and another Frenchman, Kevin Staut, riding Estoy Aqui de Muze HDC, completed the podium.
A pair of Dutch riders were close behind: Gerco Schroeder, who secured a clear round with New Orleans, and Marc Houtzager, who clocked the fastest time with Sterrehof’s Tamino but was demoted to fifth due to a downed fence on the first element of the double combination.
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