Jessica Harrington has celebrated her first Royal Ascot winner with Alpha Centauri romping home in the Coronation Stakes.

The 71-year-old Harrington, best known as a National Hunt trainer, admitted being nervous before the 1600m-Group One race for three-year-old fillies, despite being used to success at the top level in races such as the Cheltenham Gold Cup, Champion Hurdle and Queen Mother Champion Chase.

Unlucky in the Albany Stakes last year, Alpha Centauri (11-4 fav) made amends in style.

Winner of the Irish 1000 Guineas, she left a strong field that included the victors of the English and French equivalents, Billesdon Brook and Teppal, trailing in her wake.

They were nowhere to be seen as Colm O'Donoghue guided his mount home by six lengths from Threading, with Veracious third.

"I'm relieved. I got very wound up," Harringotn said.

"I was very nervous today.

"It was nice going into the Irish Guineas very much under the radar. She hadn't run well on soft ground before that. I had confidence in her. She wants good ground, I don't think she goes on heavy ground.

"Today was different. She was favourite and we were there to be shot at."

Sir Michael Stoute's record-breaking exploits got better when he took the Commonwealth Cup with Eqtidaar (12-1), who held Sands Of Mali by half a length in the hands of Jim Crowley.

Having become the winning-most trainer at Royal Ascot, the Newmarket handler enjoyed his third success of the week in a race that was only inaugurated in 2015 and had previously eluded him.

Sydney jockey James McDonald's mount Equilateral finished 12th of the 22 runners.