sentences:  With Rheingold struggling badly, Brigadier Gerard emerged as Roberto's only serious challenger but after getting to within a length of the Derby winner the favourite could make no further progress.Roberto drew away in the final furlong to win by three lengths from Brigadier Gerard in a new course record time.Brigadier Gerard finished officially 10 lengths ahead of the third horse, Gold Rod, which indicated that he had run up to his best form, however examination of the race film replay showed, and the Brigadier's owner, John Hislop, later acknowledged, that the distance between the second and third was in fact 17 lengths, indicating that Brigadier Gerard, who also broke the course record, may have run his best ever race in defeat.