It began with a 2km run along Kettle Park and Victoria Rd, before a 7km bike along John Wilson Ocean Dr.
It finished with another 2km run, following the same course as the first.
The event was first held last year and is a chance for girls and women to compete in duathlon in a supportive environment.
Bella Bloomfield was a convincing winner in 31min 56.8sec, just over three minutes ahead of Giana Thomas, who was second overall and first in the years 11-13 schools grade.
The event attracted 90 competitors.