Although his father Aidan O'Brien looks the obvious trainer to have a good day with numerous runners, Joseph has a smaller tam on the first day and some of his runners at big prices can go well.
In the opener he runs the twice raced Mythology who is looking to put it all together in the Maiden over 7f having put up two decent efforts so far.
O'Brien then fields the outsider in the Group Two Sapphire Stakes with Maria Branwell looking to outrun her odds and getting back to the form at the start of her juvenile career can see her do so.
In the feature Irish Oaks he has Lumiere Rock who ran a cracker behind Warm Heart at Royal Ascot and at an each way price again can hit the frame.
He then has Royal Ascot winner Okita Soushi in the Group Two Curragh Cup who steps up in grade but has proven his worth over this trip and can go close.
To finish the afternoon he fields Oligopoly in the Nursery Handicap and the first time tongue tie could be the key on handicap debut and then in the lucky last Coco Crush makes her debut for the yard being a well bred daughter of War Front.
O'Brien heads into the weekend sporting a strike rate of 21% for the last two weeks, managing to land six winners from his 29 runners.