The horse's early career was delayed and disrupted by injury, and he did not show his best form until switched to sprinting distances in the spring of 1979 when he won the Duke of York Stakes.
During his racing career, the horse was owned by Robert Sangster, trained by Vincent O'Brien at Ballydoyle and ridden by the English jockey Lester Piggott.
[3] Thatching began his four-year-old season in the Group Three Earl of Sefton Stakes over nine furlongs at Newmarket in which he finished fifth behind his owner's more fancied runner Hawaiian Sound.
Later in the month, Thatching started favourite for the Temple Stakes over five furlongs at Sandown Park Racecourse but finished fifth behind Double Form after hanging badly again in the final quarter mile.
Later in the month, Thatching was moved up in distance for the Sussex Stakes over one mile at Goodwood Racecourse but failed to stay and finished unplaced behind Kris.
[5] In 1978, the independent Timeform organisation gave Thatching a rating of 98,[3] thirty-five pounds below their top-rated three-year-old Ile de Bourbon.
[5] Thatching was retired from racing to stand as a breeding stallion at Coolmore's Longfield Stud at Cashel, County Tipperary at an initial fee of £8,000.