Filion was the sixth child of a harness-racing family and drove his first race at age 12. Adept, aggressive and horse-wise, he became a leading driver at Aylmer's Connaught Park Raceway when only 17. He soon was a popular idol on Québec, Ontario and northern New York tracks. Ten times  from 1968 to 1978  Filion was the leading North American driver. With more than 1.5 times the wins of his nearest competitor, he led all drivers in life purse earnings. He was inducted into the US Hall of Fame of the Trotter and the Canadian Horse Racing and Sports Halls of Fame, was named French-speaking athlete of the world, and won the Lou Marsh Trophy as outstanding Canadian sportsman.