Donnacha O’Brien bids to emulate his brother Joseph by riding a William Hill St Leger winner for their father, Aidan, at Doncaster on Saturday.
Leading Light pulled off a memorable father-son success in the world’s oldest classic six years ago.
Now O’Brien Snr is triple-handed as he goes for a Leger hat-trick – and a seventh win overall – with his youngest son on board Sir Dragonet.
The colt who started favourite for the Derby in June failed to fire on his return to action last month. However he’s upped significantly in trip and is reunited with the rider who guided him to a stunning Chester Vase success in May.
O’Brien (21) has already had three English classic winners in his short but stellar career, including Magna Grecia in the Newmarket Guineas last Spring.
Sir Dragonet looks the main threat to Logician who’s a hot favourite to give Frankie Dettori a sixth Leger.
As well as the Leger and Irish Champions Weekend, Ballydoyle’s Group One ambitions extend to Paris on Sunday where Pink Dogwood and Fleeting line up for the €600,000 Prix Vermeille at Longchamp.
Christophe Soumillon has been booked for Pink Dogwood, runner up to Anapurna in the Epsom Oaks, a race in which Fleeting was third.
The Irish fillies renew rivalry with Anapurna although it is her stable companion, the Irish Oaks winner Star Catcher, who is Frankie Dettori’s pick.
Later on the Longchamp “Arc Trials” card Wayne Lordan rides Mohawk in the Prix Niel for the which the French Derby winner Sottsass is favourite.
Joseph O’Brien’s international ambitions this weekend extend to Canada with his Naas winner Vitalogy having a first start for Qatar racing in the Grade One Summer Stakes at Woodbine on Sunday night.
Jamie Spencer travels to Toronto to take the ride and the partnership will break from stall one in the mile Grade One event.