Obama Rule looked a bright prospect when opening her account in Group Three company in the Dance Design Stakes at the Curragh.
Joanna Morgan 's charge came into the race off the back on a promising runner-up effort in a maiden at the track back in July.
The Danehill Dancer filly, who was making just her third start, came with a strong run between horses to lead well inside the final furlong.
She went on for a length success over long-time leader Shareen with Miss Laa Di Da just a head back in third.
7/2 favourite Lush Lashes returning to the racetrack after failing to get in foal to Sea The Stars, could only manage fourth.
"I've always been mad about her. I thought she was a 1m4f filly earlier in the year but everytime she's worked she's got sharper and a mile is probably her optimum trip," said Morgan afterwards.
"She wants soft ground really and I was in two minds about running her today. She didn't come down the hill very well as she was feeling it a bit.
"She's very talented and hopefully she stays in training next year. She has a great temperament.
"We train her from the field as she is prone to ulcers. She's in the Blenheim in two weeks time and then there is a race at Gowran Park for her.
"I was deliberating over whether to enter her for the Group One Prix de L'Opera in France but didn't in the end and there is always next year for that.
"She wouldn't be great to travel and if we did go there that would finish her for the season."
