He tracked the leaders for most of the way and stayed on strongly in the closing stages to finish second, beaten two and a half lengths by George Washington. Sir Percy sustained a pulled muscle in training after the Guineas and his participation in the Derby was in some doubt, with Tregoning considering the less demanding Prix du Jockey Club as an alternative target. On 3 June he started 6/1 third favourite for the 2006 Epsom Derby. The French-trained colt Visindar was the 2/1 favourite, with Horatio Nelson the 11/2 second choice. Sir Percy was held up by Martin Dwyer in the early stages and was only eleventh as the field turned into the straight. In the final quarter mile Dwyer struggled to find room for a clear run until the last hundred yards when he sent the colt through a gap along the rails. Sir Percy accelerated to take the lead in the last strides and won in a four-way photo finish beating Dragon Dancer by a short head, with Dylan Thomas a head a way in third and Hala Bek a short head further back in fourth. The race was marred by the fatal injury sustained by Horatio Nelson in the straight. After the race Dwyer called Sir Percy an exceptional horse with a "tremendous turn of foot". Martin Dwyer's ride on Sir Percy at Epsom earned him the 2006 Lester Award for Flat Ride of the Year. Sir Percy was troubled with a series of training problems which included a shoulder injury which ruled him out of a run in the Prix de l'Arc de Triomphe. On his only start after his Derby win he finished seventh of eight runners behind Pride in the Champion Stakes, when it was revealed he was still suffering the ill effects of an injury sustained in the Derby. 2007: four-year-old season Sir Percy remained in training for 2007 but failed to win in three starts. His first race of the season came in the Dubai Sheema Classic at Nad Al Sheba Racecourse on 31 March. He was struck into just after the field left the stalls but ran on to finish fourth to Vengeance of Rain. For his next race on 1 June he returned to Epsom to contest the Coronation Cup, finishing sixth of the seven runners behind Scorpion. On his final racecourse appearance Sir Percy was last of the