Before he gained fame as the trainer of 2006 Kentucky Derby winner Barbaro, Matz was an accomplished international equestrian who competed in three Olympics: 1976, 1992, 1996. At Atlanta in 1996, he was selected by the American athletes to carry the U.S. flag in the closing ceremonies. He was a member of the U.S. team that won the gold medal at the world championships in 1986, and he also won team and individual bronze medals at the world championships. Matz retired from show jumping as the top American career money-winning rider with more than $1.7 million. He began his new career as a trainer in 1998 with three horses.
In July 1989, Matz and his fiancé, D.D, who is now his wife, survived the crash landing of United Flight 232 in an Iowa cornfield. After the crash, he helped rescue other survivors, including three siblings traveling unaccompanied
Barbaro, just the sixth undefeated horse to win the Kentucky Derby, also won the Florida Derby, Holy Bull, Tropical Park Derby and Laurel Futurity. He suffered career-ending injuries in the Preakness, which led to his death eight months later. Matz secured his second U.S. classic win when Union Rags rallied to edge Paynter in the 2012 Belmont Stakes (G1).
Other top horses trained by Matz include Round Pond, Kicken Kris and Visionaire.