Ben Maher lit up the London International Horse Show as Great Britain's Olympic showjumping champions made their presence felt.
Maher won the Earls Court Olympia Christmas Cracker in dramatic fashion on his exciting eight-year-old prospect Aristo Z.
And Maher's London 2012 colleagues Scott Brash and Peter Charles were not far behind, finishing fourth and fifth among a world-class field that also included Olympic individual gold medallist Steve Guerdat, German star Marcus Ehning and Frenchman Roger Yves Bost.
Bost looked to have done enough for victory aboard Castle Forbes Myrtille Paulois, clocking 34.49 seconds to take charge of a 15 horse jump-off.
Maher, though, had other ideas as the 29-year-old capitalised on being drawn last to go by clipping 74 hundredths of a second off Bost's time and clinch the £5,300 prize.
Bost had to be content with second place, while Sweden's Malin Baryard-Johnsson (H&M Tornesch) was third, Brash (Hello Sanctos) fourth and Charles (Murka's Odie de Frevent) fifth.
"He is a crazy horse, not conventional," Maher said of Aristo Z. "He's difficult to ride, but also such fun because he always gives 100%. He can jump anything."
It proved a perfect start to the week for Hertfordshire-based Maher, who helped Britain to showjumping team gold at Greenwich Park four months ago alongside Brash, Charles and Nick Skelton.
He will bid for a second successive Rolex FEI World Cup victory at Olympia on Saturday, riding his London 2012 horse Tripple X III, and has also made a strong opening in the quest to become leading rider of the show, a coveted award that Maher won last year.
It is presented to the most successful rider across 13 of the London International's premier classes, and Maher currently lies second after four events, two points behind Brash.
Maher went top of the leading rider category after posting a third-place finish in The Mistletoe Stakes speed class.
Riding Milena, Maher clocked 50.29 seconds following another strong performance.
Essex-based Laura Renwick was second with Roller Coaster that continued her fine start to the show, with Switzerland's former world number one Pius Schwizer winning by a comfortable margin of 1.38 seconds aboard Ulysee.
Maher is now five points clear of Renwick in the leading rider race, while Bost and Italian Luca Maria Moneta have also moved above Brash, who has dropped to fifth.
Maher took his day's earnings past £10,000 by capturing the Alltech Christmas Puissance title.
Maher and Noctambule Courcelle were the only combination to make a fourth jump-off, with the puissance wall raised to 7ft 1in.
Although they nudged a brick out of it, they still finished first as his closest challenger Renwick had already withdrawn on Roller Coaster.
Renwick was second, with Guy Williams (Richi Rich) and Moneta (Quova de Vains) sharing third.
The puissance is not a counting competition towards the leading rider award.