Lying fifth on Friday night after the dressage phase, 28 year-old Waterford-born Curran delivered a fault-free cross country phase with just eight time faults and was in overnight third position.
In Sunday’s final show jumping phase the Army Equitation School rider left just one fence on the floor to finish first on a score of 57.2, just 0.4 of a point ahead of New Zealand’s triple Olympic medal winner Andrew Nicholson.
British five-time European team gold medallist William Fox-Pitt was third place, and Rolex Grand Slam winner Pippa Funnell in fourth.
Ireland received a further boost with a fifth place finish by Patricia Ryan and the Irish-bred Fernhill Cover Mist, who were lying in 11th place overnight.
Afterwards Horse Sport Ireland’s Eventing High Performance Coach Ginny Elliott said:
“I want to congratulate Geoff on a simply brilliant performance. This is a really big encouragement to the squad in their preparations for the Hong Kong Olympics”