Kentucky Derby: Aidan O'Brien denied as Justify wins at Churchill Downs
Justify maintained his unbeaten run to win the Kentucky Derby as Aidan O'Brien missed the chance to make history.
O'Brien, who won the 2,000 Guineas at Newmarket earlier on Saturday, was hoping to saddle the first European-based horse to win the race.
After heavy rain saturated the dirt track for the 144th running of the race, favourite Justify powered home by two and a half lengths.
O'Brien's Mendelssohn finished last of the 20 runners.
Good Magic was second with Audible third.
Justify has now won all four of his races this year and is the first champion since Apollo in 1882 to win the showdown for three-year-olds without running anywhere as a two-year-old.
It was a fifth victory for trainer Bob Baffert in the coveted Group One race at Churchill Downs, the first leg of the American Triple Crown.
Jockey Mike Smith, 52, won it for the second time, having first triumphed in 2005.
"When he got away clean, I felt we had a chance," said Baffert. "I knew there was going to be a hot pace, but he was doing it easily.
"It took a great horse to do what he did today.
"I'm glad it's over. This track really had me worried, I was nervous all day."