The Derrinstown Derby Trial on Sunday at Leopardstown is an Irish Group race for 3-year-olds. Naturally, Aidan O’Brien will play a major part in the proceedings.There are seven horses in the Derrinstown Derby Trial, a Group 2 over one and one-quarter miles, and O’Brien trains three of them: Recital, Memphis Tennessee, and Regent Street. But another O’Brien nominee to the Derrinstown Derby trial, Seville, was not among the final declarations, depriving the race of its most highly regarded possible participant. Regent Street and Recital finished second and third, respectively, in a Group 3 on April 10 at Leopardstown, with Regent Street leading early and holding second while Recital had a more eventful journey, rallying mildly for third. Twice-started Memphis Tennessee is unraced since winning over the Dundalk all-weather track last November.◗ The O’Brien-trained Treasure Beach scored a mild upset over favored Nathaniel on Thursday in the Chester Vase, a Group 3 Epsom Derby prep. Treasure Beach, a distant third to Frankel last year in his most recent start, finished strongly under Ryan Moore after finding room between horses in the final quarter-mile. Nathaniel, who came within a half-length of Frankel last year, briefly took the lead before Treasure Beach found room, stayed on well outside the winner and was beaten just a head in just the second start of his career. Nathaniel is trained by John Gosden.