Apprentice rider Megan Dunseath has become the first female jockey to win over the obstacles at the Warrnambool May Racing Carnival, taking out the opening race on Day 1 with Lord Pierro.

Despite being in Australia for just over three years, the Northern Ireland expat was having just her 24th ride here on the Paul Preusker-trained four-year-old in the Maiden Hurdle (3200m) on Tuesday, and although she hadn't ridden a winner in Australia, she rode Lord Pierro with plenty of confidence coming into the home straight.

The gelded son of Pierro loomed up three wide on the final bend, with Dunseath sitting quietly aboard the $8.50 hope as the pair cruised past the odds-on favourite, Portland Jimmy.

The outsider of the field – Buffalo Bill – made Lord Pierro work for his victory, but Dunseath was able to get the best out of her mount late, recording a 0.4-length victory while etching her name in Warrnambool history to the cheers of a packed crowd.

“It's a brilliant feeling,” Dunseath said on Racing.com.

“He's such a tough horse. Warrnambool is just brilliant, I love it.”

Since being in Australia, Dunseath has been apprenticed to champion jumps rider turned trainer Richard Cully, while she has recently moved in with the family of another Warrnambool legend, Shane Jackson.

Dunseath said she only found out on Monday that she had a chance at creating history, but she did not want to let that take over her mind.

“They're all a brilliant help – they're all very good and very encouraging,” she said.

“I was told yesterday (about the potential record), but I try not to think of it.”

Lord Pierro was Dunseath's only booking for the Warrnambool May Carnival, meaning she will head home with a 100% winning strike rate.