Alex Coddington and Jaydi Taylor-Chaffey put the shutters up and with GA Hannah Winnie provided cohesion as the Bay held their nerves for victory.
Dunedin went for the jugular in the first quarter for an 11-6 lead.
Poi and goal attack Hannah Winnie relayed the ball through the court to and feed Vennell but it wasn't enough as the first quarter deficit went out by a goal to leave them 22-15 down at halftime.
Taylor-Chaffey and Coddington tirelessly foraged for intercepts in the face of relentless Dunedin shooters but the gulf widened to 31-20 at the end of the third spell. The final quarter, 18-8, went to the victors.