Mazzuri (noseband) leads home Check Your Pockets (right) and Passing Trade © Photo Healy Racing
The Willie McCreery trained Mazzuri made all to take the Irish Stallion Farms EBF Fillies Handicap under Billy Lee for owners Britesavers Limited.
Successful in a maiden over the course and distance in May, the daughter of Raven's Pass then finished fourth in the Ulster Oaks at Down Royal.
Beaten a length into second on her most recent outing over the course and distance last month, the chestnut victor was sent off at 4/1 this evening.
Soon in front, she was pressed and ridden from the two furlong pole, keeping on gamely inside the final furlong to score by half a length. Check Your Pockets came through to take second under Chris Hayes for John Kiely at 7/1, while Passing Trade (7/1) was a neck back in third.
Top-weight Espoir D'soleil was sent off the 7/2 favourite, and she finished fourth.
"She did that well and Billy gave her a lovely ride from the front," said McCreery.
"We thought there would be no pace and we didn't want it to turn into a sprint but he let it turn into a sprint to suit himself which was good.
"She's improving the whole time. I thought the two of them the last day, Jessie's horse (Charcor) and herself, pulled away from over a furlong out and we didn't get penalised.
"We'll see where we go now. Billy thought she had improved another little bit and we might try and hunt for a bit of black-type for her now.
"If the ground goes though she could be in trouble a bit as she's too good a mover."
Additional reporting by Gary Carson