OZONE PARK, N.Y. - Hall of Fame trainer H. Allen Jerkens, who trained hundreds of stakes winners on the New York Racing Association circuit and engineered some of the biggest upsets in racing history, died late Wednesday afternoon in a South Florida hospital after a brief illness. He was 85.

Jerkens, known reverently by the racetrack community as "The Chief," was born on April 21, 1929 in Islip, New York, the son of a former Austrian cavalry captain who owned a riding academy. Jerkens' father enjoyed rehabilitating injured race horses and sending them back to the track, a hobby that influenced Allen to pursue a career as a thoroughbred trainer, although he started out as a steeplechase jockey.

Once he grew too big to continue riding professionally, Jerkens began training thoroughbreds, and at the age of 21, Jerkens saddled his first winner on July 4, 1950 at Aqueduct Racetrack with Populace. Two owners who helped launch his career were Eddie Seinfeld, who claimed Admiral Vee for $12,500, and Al Meser, who owned War Command, Jerkens' first stakes winner. Jerkens also was a longtime trainer for Jack Dreyfus' Hobeau Farm, for which he developed Beau Purple, Prove Out, Duck Dance and Handsome Boy.

Although he rarely ventured outside New York, Jerkens' national reputation soared during the 1970's, when he twice defeated Secretariat: first with Onion in the 1973 Whitney Handicap, and then later that same year with Prove Out in the Woodward Stakes. The monumental upsets solidified Jerkens' moniker as "the Giant Killer," which had seen its genesis a decade earlier when he sent out Beau Purple to defeat five-time Horse of the Year Kelso on three separate occasions. Other champions his horses defeated include Cicada, Buckpasser, Riva Ridge and Forego.

Overall, he trained 3,859 winners of nearly $104 million, placing him 11th and 14th, respectively, among trainers all-time.

"The men and women of the New York Racing Association mourn the passing of Hall of Fame trainer H. Allen Jerkens, not only one of the most revered horsemen of our time, but one of the finest people our industry has ever known," said Christopher Kay, CEO and President of the New York Racing Association. "'The Chief' leaves behind a lasting legacy both on and off the track. We were humbled and proud to have honored him at Saratoga Race Course last summer in our second annual Red Jacket ceremony for achievement and excellence inn our sport. Our deepest sympathies go out to his children and grandchildren."

Due in large part to twice vanquishing the immortal Secretariat, Jerkens earned the Eclipse Award for outstanding North American trainer in 1973. Two years later, he became the youngest trainer ever inducted into the National Racing Hall of Fame at the age of 45, despite not yet having trained a champion.

Jerkens' first champion finally came in 1994, when Sky Beauty won the Eclipse Award for Top Older Female.

Other notable Jerkens-trained runners include multiple Grade 1 winner Devil His Due, who won the Gotham and Wood in 1992, to go along with the 1993 edition of the Pimlico Special, Suburban, and Excelsior; Believe The Queen, who won the 1984 Tom Fool; Missy's Mirage, who won the First Flight in 1991, and the Shuvee and Hempstead in 1992; and Emma's Encore, who won the Victory Ride and Prioress in 2012.

Jerkens won many of the major stakes at Aqueduct Racetrack, Belmont Park and Saratoga Race Course, except the one that mattered most to him: the Travers, also known as the Mid-Summer Derby, which was won in 2010 and 2014 by his son, Jimmy, also a trainer. His best finish in five Travers starts came with his first entrant, Devil His Due, who was second to Thunder Rumble in 1992.

Although Jerkens sent several horses to the Kentucky Derby, he never came close to winning, with his best finish coming with Sensitive Prince, who was sixth in 1978. He also never won a Breeders' Cup race, with his best finish in 11 starts a second with Society Selection in the 2005 Distaff.

Despite his renown as a trainer, those who knew him best say his greatest success came with people, not horses. Among the trainers he mentored are Thomas Bush, Leah Gyarmati, Mike Hushion, and his two sons, Jimmy and Steven.

Jerkens, who was predeceased by his wife, Elisabeth, is survived by three sons, Allen, Steven and Jimmy, a daughter, Julie, and several grandchildren. Funeral arrangements are pending.