Turner, originally from Penicuik, is among a handful of players from Scotland to play on the Sunshine Ladies Tour.
With a two-shot lead heading into the final round, Turner carded a two-under par 68 to take the title by four shots at the Wild Coast Country Club. She was the only player in the field to finish under par.
The triumph added to her breakthrough success in the Bossey Ladies Championship in Switzerland on the Ladies European Tour Access Series in August 2017.
She said: “It feels amazing what I was able to do today.
“I can’t even begin to describe what this feels like. I have no control of what anyone else does, so I needed to keep the ball in play and hit greens in regulation and make my birdies.
“This is my second win and they both sit right up there. It’s a fabulous feeling to know you’re going home with a trophy – although I’m not sure how it’s going to fit on the plane!”
It’s a timely boost for Turner ahead of an appearance on the LET in the South African Women’s Open.
“It gives me a lot of confidence knowing I put together a lot of birdies this week, and I just need to keep that going.”
Turner revealed the reason behind wearing the purple shirt, she said: “I was diagnosed with epilepsy almost seven years ago.
“I do my bit to raise awareness for the condition and I hope to make a tradition of wearing purple in the final round, because purple is the colour for all epilepsy charities.
“Under Armour give me my clothing, and there are quite a few purple tee shirts. So all my final days are going to be purple, just like Tiger [Woods] and his red.”