Maltais, from Petite-Riviere-Saint Francois, Que., led from start to finish to extend her lead in the race for the Crystal Globe.
"It was a close final so I tried to focus on my own line," Maltais said. "I'm really happy."
Italy's Michela Moioli held off Ricker, the reigning world and Olympic champion from Squamish, B.C., for second place.
World champion Alex Pullin of Australia won the men's final by beating American Nate Holland in a photo finish. Lucas Eguibar of Spain won bronze.
Jake Holden of Caledon, Ont., was the top Canadian in 10th place.