The 22-year-old from Whistler, B.C., who battled injuries much of the year, earned her first victory of the season with a score of 80.5. She reached the podium in three consecutive events.
"I didn't have the most technical run out there, but I performed a really clean run and nailed all my tricks," said Tsubota. "It's a really great way to end the season. It's my third podium in a row. It was great being able to perform in front of people I know here."
Canadian Olympian Kim Lamarre, 26, took bronze with a score of 74.0. The top-three finish is her first since winning bronze in Sochi.
"I'm super happy with my results here even though I didn't have too much training time in Whistler," said Lamarre. "It's my first podium since Sochi. I'm proud to be back here after some injuries this season that really limited the number of events I competed in."
Great Britain's Katie Summerhayes finished second with a score of 78.33.
The top Canadian on the men's side was 18-year-old Teal Harle. The Whistler native finished fifth with a score of 83.08.
The men's competition was won by American Bobby Brown (88.67). Teammate McRae Williams finished second with a score of 87.92 and third went to France's Antoine Adelisse (86.25).