The Petite-Riviere-Saint-Francois, Que., native defeated Raffaella Brutto of Italy, Belle Brockhoff of Australia and Nelly Moenne Loccoz of France in the final at the 961-metre Seebliga course.
"I'm really happy for the win today," Maltais said. "I've been putting a lot of time and effort into the last couple years and especially this year.
"I did well in training so I was for sure expecting to do well here."
The race was cancelled Friday after weather conditions worsened following the men's event.
Hagen Kearney and Nate Holland earned the United States a victory in the men's team event, which was part of a World Cup snowboard meet for the first time.
Kearney and Holland defeated Italy's Luca Matteotti and Omar Visintin in the final, while Alessandro Haemmerle and Markus Schairer of Austria finished third.
Austria's Maria Ramberger and Susanne Moll won the women's team event ahead of Claire Chapotot and Lorelei Schmitt of France, while another French team consisting of Nelly Moenne Loccoz and Chloe Trespeuch came third.
The snowboard World Cup continues in Telluride, Colorado, next week.