DAY one of the 2025 Breeders’ Cup World Championships will surely go down as one of the most satisfying that the O’Brien family has ever had in America, as Aidan O’Brien became the outright most successful trainer in Breeders’ Cup history (thanks to a stellar Gstaad) and Donnacha O’Brien notched his first victory at the meeting with Balantina.

This all came on a Friday at Del Mar that had begun on rocky footing for the Europeans. News had broken in the morning that Ballydoyle’s Fillies’ Juvenile Turf hotpot Precise was withdrawn due to an infection - removing from play what many felt all week was the overseas banker of the meeting. Arizona Blaze was also announced as a non-runner in Saturday’s Turf Sprint.

The blows kept coming when racing began. A slow start cost Ballydoyle's Brussels dearly in the opening Juvenile Turf Sprint, flashing home for a close second behind George Weaver’s Cy Fair.

The whole dynamic shifted for the visitors in the Juvenile Fillies’ Turf, however. Co Kerry's finest, Oisin Murphy, delivered a perfectly-judged ride on Balantina to take full advantage of the favourite’s absence and provide her trainer with a day to remember. Colin Keane, riding the Andrew Balding-trained Pacific Mission for Juddmonte, stayed on well for second too.

But the most seismic achievement of the meeting was to come in the concluding Juvenile Turf.

Having been level with the legendary, late D. Wayne Lukas on 20 Breeders’ Cup wins entering this week, the Ballydoyle phenomenon went out on his own in the all-time trainer standings thanks to a performance that oozed class from Gstaad in the curtain closer. A sublime end to proceedings.

Up to this point, Gstaad had arguably O'Brien's most frustrating, if consistent, performer of the season. The Royal Ascot-winning son of Starspangledbanner was narrowly denied when second in three consecutive Group 1s before coming here, but made no mistake under the San Diego sun for a hungry Christophe Soumillon ride.

For good measure, to add to the excellent O'Brien results, Joseph O’Brien’s North Coast ran with major credit to finish third in the Juvenile Turf under Ireland’s new champion jockey Dylan Browne McMonagle.

All in all, a day that began with a feeling of disaster for the visitors all of a sudden had turned on its head. Aidan, as usual, was keen to deflect any praise regarding the milestone to the wider teams at Ballydoyle and Coolmore, but Soumillon articulated just why he believes O’Brien has managed to reach such rarified air.

“I think he's the most particular trainer I have ridden for - there's no place for improvisation,” said the Belgian, after again successfully deputising for the injured Ryan Moore.

“He's doing everything so professionally. And he respects his horses so much and also the people working for him. I think it's something amazing because everybody's going to give their life for him, and they work so hard with the horses.

“It was the first time for me when I went to Ballydoyle a few weeks ago and I was really amazed with what I saw. I've been in Japan and Hong Kong and many big stables in the world… But I've never seen something like that. I would wish to be a racehorse there.

To be honest, it's something amazing, and it's giving back to everybody, you can see.

“His sons today are also doing great. I think he's a very passionate person, a real horseman. I think he learns a lot by defeat. We are all growing up, we try hard every time. You're not going to win every time, but when we lose with something, we want to make sure it doesn't happen again. I think that's probably why he's the best ever.”

Gstaad, a half-brother to Group 1 Prix Morny and Middle Park Stakes winner Vandeek, was cut to 8/1 (from 12/1) with several firms for next year’s 2000 Guineas after this cosy victory as 6/5 favourite. It appears he will be campaigned in that direction, though there was an interesting observation made by the winning rider in the immediate aftermath.

“I think he would probably be a Guineas horse, I think that's what M.V. [Magnier] is thinking of and we’ll obviously speak to everyone involved,” said O’Brien.

“He’s a big, powerful horse. He's getting quicker. We always felt that he would get a mile, and obviously the times he has gotten beat might end up being good for him because he might not have come here and had this experience. He's a very exciting horse to have.”

The now 21-time Breeders’ Cup-winning trainer added: “I think Christophe cantered him down to the start on the dirt, and I think he said it to Michael [Tabor], M.V. and Derrick [Smith] that this horse might handle the dirt.

“Obviously it might be a big step for him to be trained as a Kentucky Derby horse next year because I think, really, in our part of the world, if you're going to do it, you kind of have to have a few trials. He's having a tough enough campaign now. I would imagine it's something that the lads could try later on. But at the moment I think he'll be trained as a Guineas horse.”

Donnacha O’Brien clearly operates with a massively smaller string than his father, but his numbers are adding up to an impressive level in top-tier races.

In the space of six seasons, the 27-year-old has now captured a mighty nine Group 1 or Grade 1 contests, and this was quite the training feat to bring Balantina to a new level after bombing out in the Debutante Stakes when last seen. It was also achieved off a 69-day absence.

As winning rider Murphy summed it up after his seventh top-level win of the year: “Donnacha learned from his dad and he doesn't complicate things. He doesn't have a huge string of horses, so he manages to find a lot of good ones in comparison to the numbers. He's provided me with winners at a very healthy strike rate. So it's great to be able to team up. He would still be riding if he wasn't a foot taller than me.”

Donnacha was full of praise for what he described as a “majestic” ride, and was by no means as surprised as the majority of racegoers by the 14/1 success.

“It feels incredible,” said O’Brien, winning the same race that stable star Porta Fortuna finished a half-length second in two years earlier.

“We've been coming here a long time, since we were babies, really. To watch dad do it year in and year out, and Joseph to get winners, it’s nice to be on the board.

“This filly's form was very strong in the early part of the year. When we ran her at the Curragh, we probably shouldn't have; they got a shower of rain literally half an hour before the race and the ground went soft. She's a really low mover.

“Then, after she disappointed there, we just gave her a bit of time and Steve [Weston, part-owner] wanted to come here. So fair play to him - he made the shout to come to the Breeders' Cup and we just worked back from here. She'd been training exceptionally the last few weeks. We came here thinking that we were overpriced and that we had a live shot.”

Balantina, a daughter of Ten Sovereigns, represented a partnership of Medallion Racing, Parkland Thoroughbreds Et Al, and part-owner Weston was keen to endorse his experience of racehorse ownership in Ireland.

“Our goal every year is to make it to the Breeders' Cup with a two-year-old. We’re fortunate enough that Donnacha and Mark McStay picked Balantina out at the Arqana sale [for €100,000 out of Camas Park Stud]. This is the dream of a lifetime,” he explained.

“I believe that we are better off, the Americans, buying our horses, leaving them in Europe for a time and letting them grow, having the advantage to compete against possibly the best turf horses in the world. And there's no reason to rush them to the States.

“If they're able to compete in Europe under group conditions, they should stay. We didn't feel right now that Balantina was at that highest level. We thought, maybe we'll bring her to the States, and maybe we could be fortunate enough to see if the Breeders' Cup will let us in. They let us in, and the horse did the rest. Oisin gave her an amazing ride.”

All told, it was an amazing day one for the visitors on the Californian coast. The O’Brien family aren’t short of special days on the international stage, but this one nearly had it all. Over to you tomorrow, Minnie Hauk, The Lion In Winter and co.

Juvenile Turf Sprint

Aidan O’Brien, trainer of Brussels (second), True Love (eighth) and Mission Central (10th)

“Brussels ran a very good race. I think the start, when he missed it a tad and got back a little bit, lost the race for him. He still ran very well. True Love just found the turns strange and maybe just found everything a bit sharp for her, really. Mission Central ran well and Dylan was happy with him. He said maybe he wanted more distance. There will be more to come with him. He said he was three-wide and would have preferred to be tucked in a little bit more, but ultimately ran well.”

Juvenile Fillies’ Turf

Colin Keane, rider of Pacific Mission (second)

“I had a brilliant run around. Obviously from a bad draw, we took our time. We ended up following the winner the whole way. We turned in and I think the pace collapsed. Oisin had to sit for a second and so did we. We got out and came home wide. With a good draw, she might have won.”

Dylan Browne McMonagle, rider of Queen Of Hawaii (seventh)

“She was slowly away and was always going to struggle after getting on the backfoot, but she did finish off well. She ran a better race than her finishing position tells you. With a better break, I think she would have been in the mix. We’re happy with her.”

Juvenile Turf

Joseph O’Brien, trainer of North Coast (second)

“Huge run. Very proud of him. Dylan gave him a great ride. He looked to be traveling easy. Very proud of how he finished. He’ll go home and point to next season.”