Owned by Thurloe Thoroughbreds and Cheveley Park Stud and trained by Henry Candy at Kingston Warren near Wantage, Oxfordshire, Kyllachy was sired by high-class sprinter Pivotal, out of Pretty Poppy, by Song. He was a fair, if unremarkable, juvenile but, nonetheless, made a perfect start to his racing career when winning a lowly median auction maiden stakes race, under Chris Rutter, at Chepstow on his debut on August 10, 2000. He was also successful in a 0-100 handicap at Sandown on his three-year-old debut; off a handicap mark of 90, he cruised into the lead, under Kieren Fallon, passing the furlong marker and won easily, by 5 lengths, from Elsie Plunkett, trained by Richard Hannon Snr.
However, it was not until 2002, when ridden on all five starts by young Irishman Jamie Spencer, that Kyllachy began the rise through the ranks that was to take him to the top of the sprinting tree. In April, Kyllachy readily won a 0-110 handicap at Newbury by 1¾ lengths, off a handicap mark of 103 and, consequently, started 2/1 favourite on his next outing, in the Palace House Stakes at Newmarket, the following month. His first start in Pattern company was a winning one, but only just; having been held up, Kyllachy barely came out best in a five-way photograph for first place, winning by a short head, a short head, a neck and a short head.
Nevertheless, Kyllachy was stepped up in class again in the Temple Stakes at Sandown in June, for which he was sent off 9/2 third favourite behind 4/1 joint favourites Invincible Spirit and Misraah. Having employed exaggerated waiting tactics at Newmarket, Spencer appear more inclined to allow Kyllachy his head on this occasion and, having made headway on the wide outside with two furlongs to run, the pair strode clear in the closing stages to beat Vision Of Night by 4 lengths, with Smokin Beau and Bahamian Pirate – who’d finished second and third at Newmarket – trailing in their wake.
The partnership attempted to extend their winning run to four in the King’s Stand Stakes at Royal Ascot just over two weeks later, for which Kyllachy started 11/10 favourite. He travelled easily throughout but, having been denied a clear run and switched inside in the closing stages, had to settle for a never-nearer third, beaten a head and half a length, behind Dominica and Continent.
The moral victor at Ascot, in the eyes of most observers, Kyllachy faced both Dominica and Continent again when stepped up to Group One company for the first time in the Nunthorpe Stakes at York in August. He started 3/1 favourite to reverse the Ascot form and so he did, but not without a daring, nay, audacious piece of riding by Jamie Spencer.
Drawn in stall 15 of 17, on the near side, Spencer deliberately missed the break, dropped Kyllachy in last and started to tack across to the far side rail. As a result of the manoeuvre, Spencer was, by his own admission, 10 or 15 lengths behind the leaders at one point but, when asked for maximum effort, Kyllachy demonstrated his trademark acceleration, forging ahead close home to beat Golden Jubilee Stakes winner Malhub by half a length. Sadly, his first Group One win was his last. Recurrent soreness behind his off-fore knee, attributed to bruising, interrupted his preparation for the Prix de l’Abbaye de Longchamp and he was retired, having won six of his 12 races and over £211,000 in prize money.