1963: two-year-old season On his first appearance as a two-year-old, Derring-Do was entered in the valuable National Stakes over five
furlongs at
Sandown Park Racecourse. He finished second to the Irish
filly Pourparler, who went on to win the following year's
1000 Guineas. He was then moved up in distance for the Imperial Stakes over six furlongs at
Kempton Park Racecourse and won from Whistling Buoy. On his final appearance of the season he returned to five furlongs for the Cornwallis Stakes at Kempton in September. Ridden by Breasley he started the
8/13 and won narrowly from the filly Golden Apollo.
1964: three-year-old season Derring-Do raced five times as a three-year-old in 1964. At
Goodwood Racecourse in July he finished second to
Roan Rocket in the
Sussex Stakes. He then recorded his only victory of the season when winning the Hungerford Stakes over seven furlongs at
Newbury Racecourse where he started at odds of 2/1. In September he finished second to the Irish four-year-old Linacre in the Queen Elizabeth II Stakes at
Ascot Racecourse.
1965: four-year-old season As a four-year-old, Derring-Do won three of his six races. He won the Cavendish Stakes at Sandown and finished third behind White Fire in the
Prix Quincey at
Deauville Racecourse. In September he was moved up in distance to contest the Valdoe Stakes over ten furlongs at Goodwood and won at odds of 4/11. Later that month he ran for the second time in the Queen Elizabeth II Stakes. Ridden as usual by Breasley, he started at odds of 9/4 and won from Ballyciptic and Minor Portion. ==Assessment==