The Henry de Bromhead-trained gelding was led in at the start of the Rentokil Initial QR Flat Race and proceeded to make all of the running under Davy Roche.
However, the Killarney stewards on the day deemed he had gained an unfair advantage and voided the race.
An appeal lodged by owner Roger Brookhouse was heard after racing at Leopardstown on Thursday evening and was not contested by the Turf Club.
Rule 209, which states "the starter's decision is final as to the fairness of the start", proved the crucial reason for the appeal going through unopposed.
The Turf Club said it intends to hold an investigation into the Killarney race.