“I definitely didn’t have this on the bingo card this week,” Osborne told ITV Sport immediately after the historic victory in the fifth and final Classic of the British Flat season.
“I didn’t even know if I would be riding the St Leger on Monday morning.”
No female jockey has won any of the other four Classics – the 1,000 Guineas and 2,000 Guineas at Newmarket and the Oaks and Derby at Epsom.
Osborne was quick to thank the trainer for giving her the ride, adding: “I have to thank Joseph and his team for putting their faith in me. It won’t change Joseph’s life, but it’s changed mine.”
The jockey is the daughter of trainer and former top National Hunt jockey Jamie Osborne, while her mother, Katie O’Sullivan is a highly-regarded equine artist.
She started as an apprentice in 2020 and finished second in the apprentice championship the following season.
Osborne went on to be crowned leading jockey in the Racing League for three consecutive seasons from 2022 to 2024.
In 2024, she became the first female jockey to win a race at the Dubai Carnival, on Ouzo, while her first Classic ride came in the same season, finishing eighth on Ed Walker’s Ten Bob Tony in the 2,000 Guineas.
Like Rachel Blackmore, the first female jockey to win the Grand National, her name will now go down in racing folklore.
Meanwhile, winning trainer Joseph O’Brien continues his love affair with the St Leger.
He won the race as a jockey on Leading Light in 2013 and claimed his first victory as a trainer in 2020 with Galileo Chrome.
Enceladus was expected to be his best chance to double his number of winners in the famous old race, having hit top form this season with three big victories, including in the Gordon Stakes at Goodwood.
But Highwayman had also showed rapid improvement this year, especially in winning the Vinnie Roe Stakes at Leopardstown.