Superstar filly Alpha Centauri has been retired after suffering a chipped fetlock in her shock defeat to Laurens in the Coolmore Fastnet Rock Matron Stakes at Leopardstown on Saturday.

The news emerged on Sunday afternoon, after the Jessica Harrington-trained filly had undergone a thorough examination at Fethard Equine Clinic.

Her defeat to Laurens ended a magnificent run of Group One wins for the daughter of Mastercraftsman, which began with the Irish 1,000 Guineas and took in the Coronation Stakes, Falmouth Stakes and Prix Jacques le Marois.

Alan Cooper, racing manager to owners the Niarchos family, told Press Association Sport: "Unfortunately the decision has been taken to retire Alpha Centauri on veterinary advice and on consultation with Jessie.

"She had a chip in her right front fetlock - which you could see her feeling in the closing stages yesterday.

"It's not a catastrophic injury and hopefully she can enjoy a successful career as a broodmare."