Favourite Big Brown won the Kentucky Derby by four-and-a-half lengths at Churchill Downs.

He beat filly Eight Belles who collapsed to the ground with two broken ankles and had to be put down in front of 157,770 racing fans.

The undefeated Big Brown had a poor stall number but worked his way through the field in the mile-and-a-quarter race and won in brilliant fashion.

Jockey Kent Desmoreaux said: "I had a beautiful trip."

He became the first horse since Regret in 1915 to win the Derby with only three previous starts.