Wedding Vow (6-1) lost her maiden tag in style when achieving Group Two honours in the Kilboy Estate Stakes at the Curragh.
The Aidan O'Brien-trained filly had disappointed on her previous start in the Ribblesdale Stakes at Royal Ascot but showed improved form when dropped down in trip to nine furlongs.
Trainer's son Joseph O'Brien brought Wedding Vow with a sweeping run to lead half a furlong from home and defeat 11-4 favourite Brooch by two lengths. Bocca Baciata was third.
The three British challengers were unable to strike a blow. Roger Varian's Talmada faded tamely after making a lot of the running, while Saeed bin Suroor's Local Time never threatened and the Ed Walker-trained Mutatis Mutandis ruined her chance by being slowly away.
"She had nice form earlier in the year but was too keen in Ascot over a mile and a half with the blinkers on," said the winning rider.
"Back in trip today she settled. There wasn't much pace on and in fairness to her she quickened up really good.
"We could think about races in America for her or the Matron or something like that. A mile or a mile and a quarter is probably her trip.
"It's good to win a Group race with a pedigree like hers."
