Yellow Rosebud, who had high-class form as a juvenile, took the Derrinstown Stud 1000 Guineas Trial at Leopardstown on Sunday.
Runner-up to Maybe in the Debutante Stakes at the Curragh last season, the filly (13-2) collared Duntle coming down the straight and ran on strongly to hold the late-charging Devotion by a length.
Trainer Dermot Weld said: "She did it very nicely, but is still a bit backward in her coat. She is a beautiful looking filly, though. She got a little tired in the last 100 yards.
"Hopefully that will set her up for the Irish 1,000 Guineas in two weeks' time. That has always been the plan.
"She ran an excellent race when second in the Debutante Stakes to Maybe last year. In France (fourth in the Prix Marcel Boussac) it was partly down to the ground and that she had gone off her coat. I was concerned about her that morning.
"She still has traces of her winter coat, but hopefully she will represent us well in two weeks."