His embarrassment of riches in the distaff division starts with Minding and is consolidated by Ribblesdale winner Even Song, Breeders’ Cup Turf heroine Found and Seventh Heaven, who already had the Irish Oaks to her name.
The year-older Found was sent off the 2-1 favourite but after a mid-season break O’Brien had been at pains to let people know she would improve significantly for the run.
And that certainly looked to be the case as she cruised into contention before blowing up in the final furlong to be beaten two and three-quarter lengths, giving weight away.
Seventh Heaven, ridden by Colm O’Donoghue in the absence of the sidelined Ryan Moore, went off at 100-30 and bar a blip in the Investec Oaks she has improved with every race this season.
O’Brien fielded four runners in all and it was the least fancied of the quartet Pretty Perfect who took the field along for much of the mile-and-a-half journey.
As she began to falter halfway up the home straight, the Sir Michael Stoute-trained Queen’s Trust moved smoothly towards the front - but the Ballydoyle big guns were waiting in the wings.
Seventh Heaven showed the best turn of foot to grab the lead and galloped all the way to the line.
O’Brien was delighted with the performances of both the winner and the second, but a liking for fast ground has him eyeing the Breeders’ Cup rather than Ascot on Champions Day.
He said: “We were delighted with Seventh Heaven at home and Colm gave her a beautiful ride.
“She’s a big rangy filly and should make a lovely four-year-old, because of that she could have an easy autumn.
“She came forward lovely from the Curragh and we thought the track and ground and trip would suit her well.
“The lads will decide what they want to do, but she’s a lot of options. She’s a beautiful traveller and is a massive, rangy filly that handles fast ground very well.
“She has plenty of class and has the option of all those fillies’ races and there’s the option of the Filly & Mare Turf in America (Breeders’ Cup) at the end of the year.
“Because she wants nice ground we’re more guaranteed to get that in America than at Ascot but as Champions Day is run on the inside course this year that could all change.”
Of Found, O’Brien added: “She was just ready to start, but she’d an awful lot of class and we knew that. She got a little bit tired and Seamus (Heffernan) looked after her.
“The plan was to go to the Curragh (Royal Whip Stakes on Sunday) and then maybe go to Leopardstown (Irish Champion Stakes) and then maybe go to France for the Arc.
“We came out a bit earlier than planned as she just had a couple of pieces of work to do.
“The lads will see the horses run at the weekend and the pattern should become apparent after that.”