Triple Crown winner American Pharoah won the $5 million Breeders' Cup Classic at Keeneland Racecourse in Lexington, Kentucky, on Saturday to end his career as horse racing's first-ever Grand Slam champion.

The Bob Baffert-trained colt, who earlier this year became the 12th horse -- and first since Affirmed in 1978 -- to win the Kentucky Derby, Preakness Stakes and Belmont Stakes, romped to a commanding 6 1/2 length victory over a fading Effinex to bring the curtain down on a spectacular career. Honor Code was a distant third.

Since winning the Triple Crown and cementing his place in racing history, American Pharoah won the Haskell Invitational but finished second in the Travers Stakes on August 29 at Saratoga in New York.

The three-year-old colt showed no signs of rust from the extended layoff, charging to the front out of the gate and never surrendering the lead.

He controlled the pace and pulled away from the pack on the final turn, to the thundering approval of a packed grandstand that had come to witness history.