"Ajax" was engaged at the battle of Cape Finisterre. Brown was embroiled in the scandal which followed and resulted in the court martial of the admiral in charge, Sir Robert Calder. Called home to give evidence at the trial, Brown placed Pilfold in charge of the "Ajax", which joined Nelson's fleet during the blockade of Cadiz. On 21 October, "Ajax" was sixth in Nelson's line for the Battle of Trafalgar and was heavily engaged with the "Intrépide" and "Argonauta", fighting them both to a standstill and remarkably only suffering two dead and nine wounded during the whole engagement. Pilfold returned home to rapturous praise in December 1805. Because the family seat, East Court Manor in Effingham, Surrey had been sold, he spent a great deal of time at Marshalls Manor, in Cuckfield, West Sussex. He was promoted to Post Captain at Christmas of that year, followed over the next ten years by further rewards, including his own coat of arms and initiation into the Order of the Bath on 4 June 1815.