Ateneo joined San Sebastian in the early lead with a 25-17, 25-18, 19-25, 25-15 victory over Far Eastern U later in the day.
The power-hitting local crew of Fille Cainglet, Alyssa Valdez and Dzi Gervacio delivered for the Lady Eagles, combining for 45 hits while Thai import Lithawat Kesinee added 13 points, including three blocks while providing the leadership for the defending champions.
Cainglet finished with 18 points, Valdez had 14 hits while Gervacio dished out a superb all around game with 13 points, highlighted by four blocks and three service aces.
Rosemarie Vargas uncorked 18 points, including two service aces, while Wenneth Eulalio added 11 hits for the Lady Tamaraws.