Foaled in Australia in 1970, Tontonan was sired by Showdown (GB) out of Forego who was a half-sister to the 1967 Victoria Derby winner Savoy. Ken Cox, the owner of Stockwell Stud had bought the British stallion Showdown in 1966 and when the colt was born with conformation issues the studmaster George Smith saw something special in the young horse. He convinced his boss to keep the colt and they formed a partnership to race him. Tontonan was sent to Bart Cummings to train and he won his first two starts in Victoria before being beaten by Imagele in the Todman Slipper Trial.
Two weeks later Imagele was a short-priced favourite to win the 1973 Golden Slipper as he was unbeaten in six starts. In one of the most dramatic moments in Slipper history, Imagele clipped the heels of another horse and fell bringing down two other runners, and Tontonan won, ridden by jockey Roy Higgins. Imagele suffered cracked ribs and his jockey Kevin Langby lay unconscious. Ron Quinton who was riding Iago was not hurt while Baron Bold’s jockey, Chris Gwilliam, suffered concussion. The three-horse fall overshadowed the victory by Tontonan from his wide gate, but a fortnight later he was sent out as favourite in the A.J.C. Sires’ Produce Stakes at Randwick and won. As he was led away to be hosed down after the race he was favoring his front legs – an indication of the shin soreness and leg problems that were to affect his career.
As a three-year-old he won the Oakleigh Plate and the Ajax Stakes before he set a weight carrying record for a 3yo in the Doncaster Handicap, defeating stars Toltrice and Coolalinga He then won the All Aged Stakes and J.T. Delaney Quality. His only loss that season was in the VRC Newmarket.
AS a four-year-old he had five races, where he won the Craiglee Stakes, John F. Feehan Stakes and Chirnside Stakes and was runner-up to his stablemate Cap d’Antibes in the Marlboro Cup. His continuing leg problems ended his racing career and he went on to become a police horse in Victoria.