Doherty's seven birdies on Thursday helped her take a slender lead over four players at five-under-par after one round of the unique multi-course event.

Golfers will play one round at Galgorm Castle and one at Massereene Golf Club before the 36-hole cut. Galgorm Castle will host the final two rounds, with a second cut coming after 54 holes.

The event is tri-sanctioned by the LPGA Tour, Ladies European Tour and DP World Tour. A field of 132 men are also playing on the same courses, and the men and women are competing for identical purses of $1.5 million ($A2.1 million).

Doherty has a one-shot edge over Lauren Coughlin and Denmark's Emily Kristine Pedersen, who both shot five-under 67s at Massereene, and England's Georgia Hall and Ireland's Leona Maguire, who shot five-under 68s, at Galgorm Castle.

The twin-course system leads to some oddities. The leading Australians in the field are Stephanie Kyriacou, who is two-under, and Karis Davidson, who is one-under, though both shot 71. Su Oh is one-under after a 72.

The 24-year-old Doherty has yet to have a top-10 finish on Tour, let alone a victory.

"I was really just trying to stay in the moment today, and I feel like I was just kind of in that mindset starting the day," Doherty said. "I stayed there and I stayed patient. I know it's kind of cliche, but it works."