Hermosa has completed a Classic double, adding the Irish 1000 Guineas at the Curragh to her success in the English version.
The Aidan O’Brien-trained filly caused a minor upset in the Guineas at Newmarket earlier this month, leading all the way as the apparent third string under Wayne Lordan.
With Ryan Moore aboard on Sunday, the result was even more emphatic.
Always up with the pace, Hermosa was a length in front with two furlongs (400m) to run as Pretty Pollyanna sat on her heels.
For a few strides it looked as though the British-trained filly could launch a challenge under Frankie Dettori, but Hermosa then began to extend.
As a sister to Hydrangea, there is no doubting Hermosa’s stamina and she drew further and further clear, giving O’Brien an eighth win in the race.
The 5-2 favourite won by four lengths from Pretty Pollyanna, with the Paddy Twomey-trained Foxtrot Liv third.
“The plan was changed to come here rather than go to the Oaks, and then go from here to the Prix de Diane in three weeks,” O’Brien said.
“She’s a lovely mare and we felt that she progressed from Newmarket. I think she showed that today.
“She could go further and her sister (Hydrangea) got a mile and a half (2400m). We’ll see how she gets on in France before thinking about that.”
Hermosa is 3-1 with both Paddy Power and Betfair for the Prix de Diane (French Oaks) at Chantilly.