Unheralded American Ryggs Johnston has won his first professional title by claiming the Australian Open by three stokes, while South Korea’s Jiyai Shin claimed her second Women’s Australian Open which was played concurrently at two courses on the famed Melbourne sand belt.

American rookie Ryggs Johnston and former world number one Shin Ji-yai win the men's and women's Australian Open titles.

South Korea's Shin Jiyai overcame late nerves and a brave charge from double defending champion Ashleigh Buhai to seal her second Australian Open title on Sunday with a two-stroke victory at a wet and wild Kingston Heath.

Lucas Herbert surrendered his outright lead of the Australian Open and will go into the final round tied with American Ryggs Johnston while South Korea’s Jiyai Shin took the outright lead in the Women’s Australian.

South Korea's Riyai Shin holds through a nervy final stretch to win her second Australian Open, while unheralded American Ryggs Johnston shocks the field to lift the Stonehaven Cup.