Racing at age two for
trainer Loyd Gentry, Jr., Proud Clarion showed little of what his pedigree promised. Out of three starts, his best result was a third in a minor race. He finished his two-year-old season with earnings of just $805. As a three-year-old, he won a few sprint races then in the immediate lead-up to the 1967 Kentucky Derby, he ran second to
Diplomat Way in the
Blue Grass Stakes. Ridden by
Bobby Ussery in the Derby, Proud Clarion was given little consideration and was sent off by
bettors at more than 30:1 odds. The fourteen-horse field included Diplomat Way,
Ruken, who had won California's
Santa Anita Derby and was the bettors second choice, plus the overwhelming favorite,
Wood Memorial Stakes winner
Damascus. Leaving the starting gate from post position seven, Proud Clarion raced ninth near the back in a pack of horses until close to the ¾ mile pole when jockey
Bobby Ussery made a move. By the mile pole he was sitting fifth then in the homestretch accelerated through an opening between Damascus and Diplomat Way. He caught front-runner Barbs Delight then raced on to win by a length in the third-fastest time in the Derby's history to that point. Proud Clarion finished third in the
Preakness Stakes and then fourth in the
Belmont to winner Damascus. He won six of his thirteen starts in 1967, with his only other significant stakes win coming in the
Roamer Handicap at
Aqueduct Racetrack in which he set a new
track record of 1:55 flat for a mile and three-sixteenths. He returned to race at age four in 1968, starting nine times out of which his best was two second-place finishes. ==Stud record==