Joseph O'Brien saw two of his runners finish second to his father

Aidan O'Brien got the better of his son Joseph twice on the opening day of Breeders' Cup action in Keeneland.

The Ballydoyle supremo took his tally of Group 1 victories this year to 27 to come within one of equaling his own record.

Sun Goddess (8/11 favourite) impressed once again with a commanding victory in the Breeders' Cup Juvenile Fillies Turf, beating Green Empress by three lengths.

Joseph O'Brien watched another of his runners, Folsom Blues, chase home his father's second winner on the card, Haffner (15/4), who gave the 57-year-old his ninth victory in the Breeders' Cup Juvenile Turf.

Remarkably, the Ballydoyle maestro secured the race for a fifth consecutive year, following triumphs with Victoria Road, Unquestionable, Henri Matisse and Gstaad, though this time the winner wasn't Ryan Moore's original pick.

That distinction had belonged to Coventry Stakes champion Great Barrier Reef, but he was withdrawn on race morning by the vet, allowing Moore to transfer rides and leaving Christophe Soumillon on the sidelines.

The victory handed O'Brien and Moore a brace on the evening and extended the Ballydoyle supremo's outright record at the meeting to 23 winners, after Bob Baffert had momentarily drawn level.

"Our horses weren't right the one day he didn't run well, they had a low-grade infection," O'Brien explained.

"He won the Acomb at York, the Royal Lodge at Newmarket and we were a little bit worried about the easy mile here but Ryan had him in a great position.

"He's by Justify so that makes him very exciting for us, the lads have covered all the good mares by him so it's very exciting.

"Ryan thinks he could get a mile and a quarter next year or even more so he's a proper Classic contender.

"We hate beating Joseph or any of the lads, we really do, but it's a business, it's sport and we don't give them an inch.

"They are not lucky enough to have the quality of horse that we have, our stock is so much better and while I'd always prefer it if they beat us, we don't ever let them beat us in any way."

Reacting to losing out to his father, Joseph said: "We're used to competing with dad and Donnacha in Ireland. We do it day in, day out, and sometimes we win and usually he wins!

"But very proud of both of our horses. They both ran super."

Meanwhile, Moore commented on the win: "He'd already won the Group Three Acomb at York which is usually a good race and a Group Two (Royal Lodge) at Newmarket.

"He's a strong galloper and he gets the mile very well. These Justifys, when they find a stride they find extra.

"He had a nice draw, he got himself in a good spot and while he was a bit idle in front, if anything had come from the back he'd have gone on again, he stays forever."