Ballot Box, in blue, gets up to collar Piper Bomb, yellow© Photo Healy Racing
Ballot Box wore down Piper Bomb to take the extended seven furlong nursery at Roscommon.
Piper Bomb kicked for home with a quarter of a mile to go and was ridden a furlong and a half down by Leigh Roche.
The pair looked to have stolen a march on the remainder but Colm O'Donoghue began to get a response out of Ballot Box.
His mount steadily cut into the lead and strongly challenged the leader in the final 100 yards to get up close home by half a length at 8/1.
Piper Bomb was a 16/1 shot with 3/1 favourite Shifting Strategy in third.
Trainer Jessica Harrington said: "She's a tough, hardy filly. I think the ease in the ground probably suited her and she stayed every yard of it.
"She will go for another nursery, and they could have claimed her last week. We are lucky around here and it's going to be hard work on horses for the rest of the day. Anything that stays will get there."
Additional reporting by Alan Magee