Edrienne Chan scored eight points in the first half as the Cougars built a 20-7 lead.
Chan finished with 19 and Christina Lundy added 16, including 12 in the second half.
Seton Catholic has clinched a spot in the playoffs, and will finish third in league if it defeats Washington School for the Deaf on Tuesday.
SETON CATHOLIC 49,VANCOUVER CHRISTIAN 33
SETON CATHOLIC — Brynn Letang 2, Coleen Murphy 2, Emma Young 2, Edrienne Chan 19, Paulina Barboza 2, Meg Spencer 2, Jessica Fernandez 0, Tessy Vetter 0, Molly Clark 0, Christina Lundy 16.
VANCOUVER CHRISTIAN — Janey Hume 0, Hannah Sound 14, Rene Espasandin 0, Faith Copenhaver 4, Anna Evanson 0, Jessamine Miller 4, Rachel Franke 9, Anna Sara Vavara 2.