Trainer Ger Lyons won his second Classic of the season as Even So took the Irish Oaks.
The 10-1 shot, a daughter of 2012 Derby winner Camelot, was guided to a two-length victory at the Curragh by jockey Colin Keane.
Favourite Cayenne Pepper (2-1) was second, with Passion (6-1) in third place.
Keane and Lyons had combined last month to win the Irish 2,000 Guineas with Siskin.
“She’s just a queen, isn’t she?” said Lyons after victory with Even So, the first horse he has trained for owners from the powerful Coolmore Stud team.