City of Troy won the Derby on Saturday to give trainer Aidan O'Brien a record-extending 10th success in the Epsom classic.

The 3-1 favourite put a dismal run in the English 2,000 Guineas behind him to seal the Blue Riband, just as O'Brien's Auguste Rodin had done 12 months ago.

"It was hard to know what would happen today but we still thought we had the best horse. It just didn't happen in the Guineas," said jockey Ryan Moore, partnering his fourth Derby winner.

City of Troy beat Ambiente Friendly (9-2) with another O'Brien runner Los Angeles (6-1) in third. (AFP)