Irish riders claimed the weekend’s richest two prizes in world show jumping when Cork’s Billy Twomey won the Amsterdam Grand Prix this afternoon (Sunday), half an hour after Jessica Kurten had triumphed in the German World Cup Qualifier in Leipzig. Kurten claimed the 39,600 euro top prize when she triumphed over Australia’s Edwina Alexander and France’s Pénélope Leprevost in a 15 horse jump-off.