JUSTIFY has won the US Triple Crown.

The Bob Baffert-trained chesnut, who was unraced as a juvenile, broke well under jockey Mike Smith and made all for a comfortable one-and-three-quarter-length win in the 12-furlong Belmont Stakes in New York.

He is the 13th horse to sweep the Kentucky Derby, Preakness Stakes and Belmont Stakes treble, and he joins 1977 hero Seattle Slew as an unbeaten winner of the series.

Former Jeremy Noseda-trained Gronkowski, who won a listed contest at Newcastle in late March and was making his US debut for Chad Brown, was the one who chased him home.

The Bill Mott-trained Hofburg was third in the famous Juddmonte Farms colours.

The previous US Triple Crown winner came in 2015 – American Pharoah, who now stands at Ashford Stud in Kentucky, the former home of Justify's late sire Scat Daddy.