Aidan O'Brien pulled off the old one-two in the Group 3, $106,000 Chester Vase at Chester Racecourse south of Liverpool on Thursday, as his 25-1 Golden Sword held off his 8-1 favorite Masterofthehorse by two lengths.\nSeemingly sacrificed as a rabbit for his strongly backed stablemate, Golden Sword led throughout under Colm O'Donoghue, getting the 1 1/2 miles on good to firm ground in 2:33.86, or .34 of a second faster that the track record set by Old Vic in 1989. Debussy, the second choice at 5-2, was third, 1 1/2 lengths behind Masterofthehorse.\nA son of High Chaparrral, Golden Sword had finished only fourth in the Group 2 Prix Noailles at Longchamp five weeks ago. His chances were discounted in the Vase in part because the Noailles winner, Grandcamp, had finished last of five in the Group 2 Prix Hocquart on Monday.\nO'Brien will saddle the favorite for Saturday's Group 3, $98,000 Lingfield Derby Trial in Age of Aquarius. A Galileo half-brother to Group 1 Prix Jean Prat winner Turtle Bowl and to Group 1 Prix d'Astarte winner Turtle Bow, Age of Aquarius was fourth to stablemate and Epsom Derby second favorite Fame and Glory in the 1 1/4-mile, Group 1 Criterium de Saint-Cloud last time on Nov. 12. He will be opposed in the 1 7/16-mile test by the Henry Cecil-trained maiden winner Father Time, a Dansili full brother to 2006 Criterium de Saint-Cloud winner Passage of Time, and by Alwaary, an improving John Gosden-trained son of Dynaformer.