The pair finished first and second in 2011 and both are obviously previous winners but it might just be the recently crowned Australian Amateur Champion Minjee Lee will have a bit to say in the outcome of the event.
Hedwall and Lee have a one shot lead over Ko through 36 holes of the event, tomorrow's final round shaping as a gripping finale.
All three added second rounds of 69 today while two shots behind Ko are the experienced Queenslander Sarah Jane Smith and West Australian Kristie Smith.
Victorians Stacey Keating and Bree Arthur and South Australian are one shot further back and only four from the lead so there are still many chances to take the title.
Hedwall appeared as if she might take a significant lead when she eagled the 5th to go four under for the day and 10 under for the tournament but she essentially tread water from there and yet another bogey free round allowed Lee to catch her.
Lee has not had a bogey in her opening 36 hoes and the current Australian Amateur and US Girls Champion is likely to prove a tough opponent for Hedwall and Ko tomorrow.