Jessica Harrington became the second trainer in two days to celebrate a first Classic success after Alpha Centauri won the Irish 1000 Guineas at the Curragh on Sunday.
On the previous day, Romanised provided Ken Condon with his first Classic success when winning the Irish 2000 Guineas under jockey Shane Foley.
O’Brien, chasing a record eighth Irish 1000 Guineas prize, had to settle for the minor placings with Could It Be Love under the trainer’s son Donnacha O'Brien and Happy with Ryan Moore atop, finishing second and third respectively.
Godolphin bidding for their first success in the race with Soliloquy could finish only fourth in the 13-runner field.
Harrington said Alpha Centuari’s triumph was on a par with her Cheltenham Gold Cup winner Sizing John in March last year.
“It's a fantastic result, our first Classic win having been placed in a few of them,” she said in her post-race television interview.
“Today was the first time since she ran second in the Albany at Royal Ascot that she got fast ground and that seems to be the key to her. We'll let the dust settle but I'd imagine she'll go for the Coronation Stakes next.”
Winning jockey Colm O’Donoghue rode a patient race. He stayed in the middle of the pack as Could It Be Love, one of four O’Brien entries, blazed in front with William Buick on board Soliloquy heading the chasing pack.
O’Donoghou pushed along the Mastercraftsman filly from fourth to chase the leaders as they approached the 400-metre mark before moving to second and finishing strongly to win by a length and-a-half from Could It Be Love.
Alpha Centauri was a runner-up in the Albany Stakes at Royal Ascot last year but she was well beaten on her seasonal return at Leopardstown in April.
“She ran here in the Moyglare on soft to heavy and her first run this year was on soft to heavy ground. She’s a big, big filly and she just can’t pull herself out of the heavy ground," Harrington added/
“She’s some big lady, but she’s a beautiful filly and she’s gone and done it today, so onwards and upwards.
“I’d say we’ll look at Ascot. She’s a lovely filly to have and there is a lot of work gone into this. It’s not just me, there are an awful lot of people back at home who have done unbelievable work.”