The news came after another contestant - 26-year-old Denise Garrido from Bradford, Ont. - was crowned Miss Universe Canada over the weekend.
Organizers of the pageant came forward this week and alleged that a typographical error had led to the erroneous crowning and moved quickly, and silently, to pass the title on to Santos.
Shortly after the announcement, Santos acknowledged her turn in fortunes on her webpage.
"I would like to say thank you to God, my family, friends, and all of my supporters during this humbling yet rewarding journey to become Miss Universe Canada. I can't begin to express my gratitude and excitement to represent Canada on the international stage. It's an honour to represent our country and I ask you for your continued support and prayers."
Santos' Twitter feed quickly took off with well-wishes from friends, family and fellow Calgarians.
— Riza Santos (@Riza_Santos) May 29, 2013
Even be-everywhere, wealthy businessman and TV star W. Brett Wilson congratulated Canada's latest pageant ambassador.
The embarrassing error comes a year after a controversial decision was made (and then reversed) to eliminate transgender contestant Jenna Talackova from participating in the Miss Universe Canada pageant.
Santos is a model, actress, engineer and former Canadian Forces member.
Click through the slideshow below for more on Santos.