He said: "To win the world's most testing indoor competition is an amazing tribute to the quality of Irish breeding and I want to congratulate the breeders Edward and Catherine Doyle and, of course, the American rider Rich Fellers for his tremendous skill.
"I believe it is also a testament to the soundness and longevity of the Irish Sport Horse that a horse like Flexible can not only continue to compete at the age of 16, but also beat the world's best in the very toughest of competitions."
Flexible was previously runner-up in the World Cup Final at Gothenburg in 2008, while his sire, the famous Irish stallion Cruising, was runner-up with Derry's Trevor Coyle in 1999 at the same venue.
Meanwhile, Alexander Butler and the Irish-bred gelding Will Wimble also snatched victory in the Lummen Grand Prix in Belgium recently. The 12-year-old grey gelding by Touchdown (ISH) out of The Woolsack (ISH), by Roselier (TB), was bred by Harold McGahern from Co Longford.
In France, Paddy O'Donnell from Fenor in Co Waterford rode Thomas Power's Clover Flush mare Harristown Princess to victory in the Grand Prix qualifier.
The 25-year-old rider beat Britain's Laura Renwick and Oz de Breve by just under a third of a second and also saw off challenges from top British riders Ellen Whitaker, Tim Stockdale and Guy Williams to take the €6,000 prize.
O'Donnell's win came after fellow Irish rider Shane Breen had come out on top in a 16-horse jump-off the previous day. Riding another Irish-bred, his own Olympic Lux gelding Cos I Can, Breen saw off challenges from British runner-up Tim Stockdale and the Irish-bred Kalico Bay Fresh Direct.
Cos I Can (ISH) is a nine-year-old bay gelding by Olympic Lux (KWPN) out of Carel View Lass (ISH), by Harlequin De Carel (SF). He was bred by John Griffin, Ballyvogue House, Asketon, Co Limerick. Harristown Princess (ISH) is a 1998 chestnut mare by Clover Flush (ISH) out of Jasusa Kildalton (ISH), by Kildalton Gold (ID C1).
However, notable Irish Sport Horse performances were not confined to showjumping, as they were also out in force at the famous Rolex Kentucky three-day event in the USA.
No less than four Irish-bred horses finished in the top 15 at the end of three gruelling days.
Cruising son Mr Medicott, with the USA's Karen O'Connor on board, placed fourth, on equal points with the USA's Boyd Martin and Otis Barbotiere, who squeezed into third with the benefit of a faster cross-country time. Mr Medicott was bred in Co Kerry and was a Beijing Olympic Team Gold Medallist for Germany in 2008.
Won this year by Britain's William Fox-Pitt (GBR) on the New Zealand thoroughbred Parklane Hawk, Kentucky saw the Irish Sport Horse Mighty Nice take 10th place with the USA's Phillip Dutton, with two other members of the Irish Sport Horse studbook filling the next places on the leaderboard.
Canada's Peter Barry placed the Tipperary-bred bay gelding Kilrodan Abbott in 11th, while Phillip Dutton rode the Co Antrim-bred gelding Fernhill Eagle into 12th place.
Irish Sport Horses were certain of adding to their reputation as solid event horses at Badminton last week, until atrocious weather conditions forced the cancellation of the famous competition.
Of the 92 horses on the accepted entries list for Badminton, 26 were Irish Sport Horses, with a further 15 Irish Sport Horses waiting on the reserve list.
Two of the most remarkable horses due to tackle Badminton were Lenamore (ISH) and Comanche (ISH).
Aged 20 and 19 respectively, few horses could match these two for their number of completions at Badminton. Lenamore (ISH) has completed the course a massive eight times, while few horses could match Comanche (ISH) for the number of starts (nine) or completions (seven).
However, given their ages, it would seem unlikely that either horse will still be competing next year in an attempt to add another Badminton performance to their tallies.