From 2008 to 2010, he was stable jockey for Coolmore, taking over from the drug-banned Kieren Fallon. He had been riding for them on an ad-hoc basis since 2002, most notably winning the Derby on High Chaparral in 2002. In 2008, he rode 19 Group One winners in a single season for O'Brien (21 in total for Coolmore), and followed it up in 2009 with another 10, including the Irish Derby, Queen Elizabeth II Stakes, Sussex Stakes, Ascot Gold Cup, St. James's Palace Stakes and an Irish 1,000 and 2,000 Guineas double.