The disastrous first round that morning, in which Foxhunter incurred 16.75 faults and at one stage became perilously close to losing his jockey, was forgotten in the euphoria of victory - except by Harry Llewellyn himself. Many years later he was to recall his anguish after that first-round disappointment in his autobiography, Passports to Life (1980). "I had failed to warm up Foxhunter adequately . . . we were lying only sixth in the Grand Prix des Nations - and it was all my fault. I was shattered."
Afterwards he managed to sleep for an hour (the equable Foxhunter also slumbered peacefully between rounds) before returning to the Finnish arena, thoroughly warmed up and "raring to go", to complete their second round clear, which gave Britain victory.
He insisted that the praise which was heaped upon him during the celebrations which followed was undeserved - for, as he told everyone he met, his two team-mates had achieved better overall scores in the two rounds: Wilf White for a total of eight faults and Duggie Stewart with 16. But it would be the celebrated Welshman's heroic retrieval of a seemingly lost cause that was to go down in equestrian history.
Llewellyn had bought Foxhunter as a six-year-old and went on to win a team bronze medal with him at the Olympic Games in London in 1948. Together they were to win a remarkable total of 78 international competitions (including three victories in the King George V Gold Cup in 1948, 1950 and 1953) before the horse retired in 1956. They remain one of the greatest and best-loved partnerships ever to grace the British show-jumping scene. Foxhunter's name has lived on through the annual championship for novice horses at the Horse of the Year Show (which, in terms of the numbers competing in the preliminary rounds) is the biggest show-jumping contest in the world.
Llewellyn's first great achievements in the horse world were gained as an amateur steeplechase jockey. He won 60 races under National Hunt rules between 1931 and 1950, as well as having two memorable rides in the Grand National on Ego with whom he finished second in 1936 and fourth in 1937.
On the latter occasion he had (as usual) to do battle with his weight, reducing it from 12 stone to 10 stone 4lb with the help of running and dieting. After sweating the last pounds off during a three-mile run on the day before the race (while zipped up in an airman's suit with many layers beneath it) he finally made the weight. Ego, who started favourite, had looked the likely winner until a riderless horse ran across him at the last open ditch, causing him to plunge right through the fence and be brought back to a standstill. It was no mean achievement to finish fourth after that debacle.
In October 1939, shortly after the start of the Second World War, Llewellyn secured a commission in the Warwickshire Yeomanry - mainly, he believed, as the result of the reputation he had gained during his steeplechasing exploits with Ego. He was to take part in several major campaigns and was on General Montgomery's staff from November 1942 until the end of the war in Europe, part of that time as Senior Liaison Officer at Eighth Army headquarters.
He rose to the rank of Lieutenant-Colonel, was twice mentioned in Dispatches, and was decorated with the US Legion of Merit and appointed OBE. His services to Wales were later to be rewarded with a knighthood in 1977.
Always debonair and charming, Harry Llewellyn played many roles in the administration of show jumping - among them Chairman of International Affairs, chef d'equipe of the British team, Chairman of the British Show Jumping Association (from 1967 to 1969) and more recently the Honorary Vice-President of the association.
He was chef d'equipe during the Mexico Olympics of 1968, where David Broome appreciated his diplomacy in keeping the team happy. "Once or twice he must have felt like squaring the lot of us, but he resisted the temptation and took the diplomatic way out instead. I've admired him for this ever since."
"Sir Harry was a legend in his own lifetime," says Andrew Finding, the current chief executive of the BSJA. "His was an era of show jumping that to this day we aspire to emulate. His knowledge and experience were second to none."
Henry Morton Llewellyn, show jumper and jockey; born Aberdare, Glamorgan 18 July 1911; OBE 1944, CBE 1953; Kt 1977; succeeded 1978 as third Bt; Chairman, British Show Jumping Association 1967-69; married 1944 The Hon Christine Saumarez (died 1998; two sons, one daughter); died Llanarth, Monmouthshire 15 November 1999.