Natroun over 2400 metres at Longchamp Racecourse on 7 May. Two weeks later he contested the Prix de l'Avre over the same course and distance and won by five lengths from Bilal. Following the race, the colt's owner paid a supplementary entry fee of approximately £15,200 to enter the horse in the Prix du Jockey-Club, reportedly at the urging of Saint-Martin. On 7 June, Natroun contested the 150th running of the Prix du Jockey-Club over 2400 metres at Chantilly Racecourse. In France, horses in the same ownership or stable are coupled for betting purposes. The Vincent O'Brien pair Ancient Times and
Prix du Lys Prix du Jockey Club or the Prix de Diane. The Prix du Lys was cancelled in 1940, and was held at Longchamp in 1941 and 1942. It was run at Le Tremblay over 2,300 metres in 1943 and 1944, and at Longchamp again for three years thereafter. The exclusion of Prix du Jockey Club and Prix de Diane entrants ended in 1970. The race was closed to fillies and opened to geldings in 1986. The Prix du Lys was contested over 2,800 metres at Saint-Cloud from 1993 to 1996. In the following years it was run over 2,600 metres at