Ajax 1 beat Varsity A 55-51 in a thrilling semifinal to book a place in Saturday's final, in which it will play Magic A.
But victory could have easily eluded the defending champion.
Experienced Ajax guard Janet Main missed two free throws in the dying moments of the game.
But Varsity was not able to secure the rebound and Nicole Ruske drained a three-pointer on the buzzer to stretch the final margin to four points.
Varsity had led by five with four minutes to go in what was a seesawing match.
Meanwhile, the Magic was undefeated during the round-robin with five consecutive wins, including a 76-55 win against Ajax.
It also beat its rival 86-83 during a playoff match earlier, but do not write Ajax off.
Both sides are playing some terrific basketball and the final shapes as a tight encounter.
