Waters used her incredible speed around the court and the power and accuracy of her shots to surprise Song, who was on the back foot from the start of the match.
The South African took the first game in a tiebreak then dominated her opponent after that, holding her nerves to clinch her first major trophy.
She said while she was happy with her movement, her shot making had been the difference.
“My speed around court has been working well, my speed is one of my strengths, but I think the accuracy of my shots is what contributed today.
“I was able to put her under a lot of pressure today and I’m very happy about that.
“It’s still sinking in,” she added.
“I’ve finally sealed the deal. I’ve come close a few times, losing 3-2 a couple of times, so to finally win it three-love is a nice surprise.
“I spent a week with Malcolm Willstrop a couple of weeks ago which I think was a tremendous help.
“It was such a short amount of time but it had the right effect.”
In the men’s tour, Brisbane’s Zac Alexander stamped his authority on the rest of the field when he took out the title without dropping a game throughout the tournament.
The top seed downed German giant killer Raphael Kandra 11-7, 11-7, 11-1 to claim his first Queensland senior title after winning multiple junior honours.
The New York-based Alexander was using the Queensland Open to fine tune his game head of qualifying for the Australian Open next month.
“I didn’t concede a game all week, which was sort of my goal at the start of the tournament,” Alexander said.
“It was tough today, I’d never seen or heard of him before but I knew he was a giant killer.
“He upset the number two seed, the number six seed and the fourth seed this week, so I didn’t know what to expect.
“It was tough for the first two games but I think by the end he was feeling the effects of his long week.”
Alexander was thrilled to add the senior title to his trophy cabinet.
“I won a few junior titles but to win the senior one is really good and hopefully it will give me a bit of confidence going into qualifying for Canberra,” he said.
Final results (prefix denotes seeding):
(4) Siyoli Waters (RSA) bt (2) Song Sun Mi (KOR) 13-11, 11-6, 11-6
(1) Zac Alexander (Qld) bt Raphael Kandra (GER) 11-7, 11-7, 11-1