Danica Jose notched a double-double with 11 points and 16 rebounds while Sam Ong added 11 points as the Lady Eagles marched into their first post-season appearance since they won it all in 2007.
Ateneo faces third seed Adamson in a knockout game with the winner going up against second-ranked De La Salle University, which holds a twice-to-beat advantage.
Titleholder Far Eastern University, which claimed the outright Finals berth after sweeping the elimination round, will also have a rare thrice-to-beat edge.
Risa Paig paced the Lady Bulldogs with 14 points while Joi Tolentino chipped in with 11 markers.