On June 9, 1973, Secretariat won the Belmont Stakes by thirty - one lengths in a record time of 2: 24, becoming a Triple Crown champion, ending a 25 - year gap between Citation, the Belmont and Triple Crown winner in 1948. Secretariat 's record still stands as the fastest running of the Belmont Stakes and an American record for 11⁄2 miles on the dirt. In 1977, Seattle Slew became the first horse to win the Triple Crown while undefeated. Affirmed was the last winner of the Triple Crown in the 20th century, taking the Belmont Stakes in 2: 26 4 / 5 on June 10, 1978. Ridden by eighteen - year - old Steve Cauthen, Affirmed defeated rival Alydar with Jorge Velasquez in the saddle. At the time the race was the third - slowest start and the third - fastest finish with the quarter in 25, the half in 50, 3 / 4 in 1: 14, the mile in 1: 37 2 / 5.
what is the fastest time at the belmont stakes
2: 24