The American entered the event in her country's capital as the reigning Jumping World Cup Final champion following her victory in Paris in April.

She again rode Breitling LS in Washington D.C and triumphed after a four-rider jump-off.

Madden went clear twice and was quickest second time around as she clocked 30.74sec.

Kate Dinan and Dougie Douglas also went clear in the jump-off in a time of 32.93 for second.

An all-American top three was completed by Lucy Davis and Caracho, who went clear twice and finished the jump-off in 33.44.

Madden is already qualified for next year's World Cup Final in Gothenburg thanks to her victory in Paris, but has showed no sign of slowing down.

"This was Breitling's first indoor this year, it's nice to see he's in form," said Madden, a team jumping Olympic gold medallist at Athens 2004 and Beijing 2008.

"It just shows why he was so good at World Cup Finals.

"He walked right in here, and he's clever, rideable, adjustable, careful, and he can handle tight spaces like this."

In the North American League East sub league standings, United States rider Molly Ashe Cawley tops the standings as athletes battle for a place in Gothenburg.

She has 29 points, with compatriots Davis and Georgina Bloomberg both on 28.