(CNN) — American Pharoah, the odds-on favorite, became the 12th horse to win the Triple Crown, winning the Belmont Stakes on Saturday evening.

The 3-year-old bay colt led wire-to-wire and defeated second-place Frosted by a comfortable margin.

He is the first Triple Crown winner since 1978, when Affirmed won the Kentucky Derby, Preakness Stakes and Belmont Stakes.

American Pharoah was the only horse in the race who had run both the Kentucky Derby and the Preakness. But he showed early he didn’t have tired legs.

Trainer Bob Baffert and jockey Victor Espinoza each won their first Triple Crown with American Pharoah after multiple prior attempts.

Until Saturday, 13 horses since 1979 had won at Churchill Downs and Pimlico but failed to triumph at Belmont.

In 1978, Affirmed, ridden by Steve Cauthen, defeated second-place Alydar in three exciting races.

Triple Crown winners

1919 — Sir Barton

1930 — Gallant Fox

1935 — Omaha

1937 — War Admiral

1941 — Whirlaway

1943 — Count Fleet

1946 — Assault

1948 — Citation

1973 — Secretariat

1977 — Seattle Slew

1978 — Affirmed

2015 — American Pharoah