At age two, Polynesian lost his first three races, then bucked his shins. From that he developed azoturia (horsemen call it "tie-up" which is a tenseness of the loin muscles which makes urination difficult). Polynesian, in order to recover, was allowed out in a paddock, but became frightened of moving a muscle in case of more pain, so the horse stood there. It took a lot of tugging to get him into his stable at night. His trainer, ex-steeplechase rider Morris Dixon was reduced to thinking he might have to crack him over the rump with a whip, but was saved when a swarm of hornets stung the colt and Polynesian knew he could run again.
Back in training at age three, Polynesian won five of his next seven starts, one of which was a division of the Sagamore Stakes. In the Experimental Free Handicap he came in third to to Jeep and Greek Warrior, and fourth in Hoop, Jr.s division of the Wood Memorial. He skipped the Kentucky Derby (won by Hoop, Jr.), instead competing in one mile Withers Stakes where he defeated Pavot. Polynesian then took the mile and three sixteenths second leg of the U.S. Triple Crown series, the Preakness Stakes, in a front running victory. Because of its demanding one and a half miles, Polynesian was not entered in the third leg of the Triple Crown, the Belmont Stakes. Later that year he won the Saranac Handicap.
Polynesian developed into a champion sprinter, winning a number of important sprint races in 1946 and in 1947 and was named the U.S. Champion Sprint Horse. In his last year of racing, he went through a streak of five wins, 10 seconds, and 10 thirds.
At age seventeen, Polynesian died in 1959 from colic and was buried at Gallaher Farm in Lexington, Kentucky.