The partnership went top of the overall North American League East Coast standings as a result of their victory in the Californian city.

Twenty-five combinations started the event which provided Genn's first FEI World Cup victory.

The course tripped up several riders as the first clear run was only achieved by the 14th pair.

"My horse felt great," said clear round jumper Genn, who then won the jump-off with the quickest time of 36.88sec.

"I like to plan things, so before we came here, we showed in Kentucky, because they have a Grand Prix Friday night under the lights.

"That was our warm-up, and we jumped very well there, so I felt pretty confident."

Home favourites Karrie Rufer and Karl Cook took second and third respectively as six partnerships went clear again after the jump-off.

Rufer rode Georgie d'Auvray EC into second place in a time of 37.31 while Cook and Caillou finished in 38.47.

Genn credited the full crowd for his win as it gave a boost to Bugatti.

"I was hoping I got a chance to run for it today, and it worked out," he said.

"Bugatti likes the footing, and he likes the crowd - it gets him a little excited, and that makes him better, because normally he's a very lazy horse.

"It all kind of played a little bit in my favour."

Genn now moves up to the top of the East Coast overall standings with 20 points.

He is joined at the top by Molly Ashe Cawley of the US who also has 20 points following her victory in New York.

In the West Coast standings, Rufer moves up to the top with 21 points.

With her second place finish in Sacramento, she adds 17 points to her overall tally, adding to the four points she scored in Vancouver, Canada.

Vancouver was the first qualifier of the 2018-2019 season.