Irish-based Man of Iron wore down nine-year-old gelding Cloudy's Knight in the stretch to capture the $500,000 (300,824 pound) Breeders' Cup Marathon by a nose at Santa Anita Park on Friday.

Ridden by Johnny Murtagh and trained by Aidan O'Brien, the Kentucky-bred chestnut colt won for the fourth time in 10 career starts.

Man of Iron, a half-brother to Belmont Stakes winners Jazil and Rags to Riches, took the mile-and-three-quarters affair in 2:54.11.

Favourite Mastery, ridden by Frankie Dettori, finished third in the 10-horse race over Santa Anita's Pro-Ride synthetic surface.

The Marathon was the opening Breeders' Cup event at the two-day world championships.

(Writing by Steve Ginsburg, editing by Dave Thompson)