Stolz defeated David Bronson, both from New South Wales, who earlier had forced a playoff by making birdie at the 18th.
Stolz and Bronson together finished at 8-under-par for the tournament, one shot ahead of overnight leader Andrew Bonhomme of Queensland.
Bronson was looking to extend the playoff but three-putted to give the title to Stolz.
Bonhomme who had a comfortable four-shot lead going into the final day, stumbled home with a 3-over 73 and missed out on the playoff by a shot.
Marc Leishman, who shared the overnight lead with Bonhomme, finished fifth with a disappointing 76.