Aidan O’Brien sees off challenge of son Donnacha as San Antonio claims Boodles Dee Stakes

Trainer Aidan O'Brien© PA

Father beat son in the Boodles Dee Stakes as Aidan O'Brien's San Antonio repelled the Donnacha O'Brien-trained Alder at Chester.

Alder was the 11-10 favourite for the Listed contest following an impressive start to his season at Cork, with San Antonio sent off at 16-5 following victory on the all-weather at Dundalk.

As is usually the case, Ryan Moore had San Antonio well positioned throughout, allowing his mount to stride to the front while his rivals jostled for position in behind.

Gavin Ryan delivered Alder with a major challenge rounding the home turn, but San Antonio refused to yield in front and passed the post with a length and three-quarters in hand to give O'Brien a 10th victory in the race.