Matthew Byrnes began his association with Thoroughbred racing as an exercise rider before becoming an accomplished jockey. However, it was his skill as a conditioner of racehorses that garnered Byrnes lasting acclaim.
After his days as a rider ended because he had trouble making weight, Byrnes, a native of Ireland, began training under the tutelage of future Hall of Famer Jacob Pincus. Byrnes was then hired by famed sportsman Pierre Lorillard to become the head trainer for the Master of Rancocas stable.
Byrnes quickly made a name for himself when he took over the conditioning of future Hall of Famer Parole in 1881. As an 8-year-old in 1881, Parole won 12 of 24 starts for Byrnes and followed that with 15 wins and 18 other in-the-money finishes among 42 starts in 1882 and 1883.
In 1885, Byrnes won the Suburban Handicap with Pontiac. Byrnes also won the Suburban in 1890 with future Hall of Famer Salvator and in 1892 with Montana.
In 1887, Lorillard stepped away from the sport and Byrnes began his association with James Ben Ali Haggin’s powerful stable. Byrnes guided Haggin’s mighty Salvator to a spectacular career mark of 16-1-1 from 19 starts. While under the care of Byrnes, Salvator set American speed records for one mile and 1¼ miles as a 4-year-old in 1890.
At the same time he was training Salvator, Byrnes also enjoyed tremendous success with the great mare Firenze, another future Hall of Famer. From 1886 through 1891, Firenze won 47 races for Byrnes and was in the money 77 times in 82 starts. Firenze regularly defeated males, including wins over Hall of Famer Hanover at three distances, and two wins over Hall of Famer Kingston, the Thoroughbred that won the most races in the history of the sport.
When Haggin got out of the Thoroughbred business in 1891, Byrnes went to work for Marcus Daly. For Daly, Byrnes trained a number of quality horses, including Tammany, Montana, Senator Grady, and Scottish Chieftain, the 1897 Belmont Stakes winner. Daly died in 1900 and Byrnes called it a career as a trainer. Byrnes then bought a farm opposite Monmouth Park in New Jersey. A few years later, Byrnes sold the farm and moved to California to work as a bloodstock advisor.
In his later years, Byrnes returned to New Jersey and often attended the races at Saratoga. He died in Asbury Park, N.J., in 1933 at the age of 80.