Twilight Alley was a "giant"[1] chestnut horse, standing over seventeen hands high with a narrow white blaze[2] bred by the stud of Sir Victor Sassoon.
In May 1963, Twilight Alley contested the inaugural running of the Henry II Stakes over two miles at Sandown Park Racecourse and finished second behind Gaul.
Piggott sent the favourite into the lead after a quarter of a mile and opened up a clear advantage before easing the pace to allow the horse to have a "breather" six furlongs out.
Twilight Alley accelerated again on the turn into the straight and held off the challenge of Misti to win by a length, with Taine in third and Balto in fourth.
[1] In July, Twilight Alley started 7/2 favourite for the thirteenth running of Britain's most prestigious weight-for-age race, the King George VI and Queen Elizabeth Stakes over one and a half miles at Ascot.