Homecoming Queen denied Fire Lily in the Leopardstown 1,000 Guineas Trial Stakes.
Aidan O'Brien's filly (8-1) dictated the tempo from an early stage but looked likely to be swallowed up approaching the final furlong.
Favourite Fire Lily (7-4) loomed up going well on the outer under Wayne Lordan but she seemed to lose momentum in the final 100 yards and it was Colm O'Donoghue's mount who prevailed.
A whole host of horses held a chance turning for home as the field bunched up but it was eventually 9-2 chance Up, another O'Brien runner, who stayed on best for third.
O'Brien said: "She is a hardy little filly and she improved nicely from the Curragh (ninth on March 25).
"She will go into one of the Guineas now."