Dindin Santiago came away with 16 points for the Lady Bulldogs, while Carmina Aganon chipped in 13, including three service aces.
NU is currently in solo lead with a 2-0 slate.
Sarina Bulan led the Lady Warriors with eight points, while Jasmine Alcayde added seven.
UE remains winless after suffering its second straight loss.
Valdez finished with 23 points, from 19 spikes and four services aces, while Ahomiro added 13 and rookie Anna Gopiko with 12.
Geneveve Casugod, on the other hand, produced eight markers for the Lady Tams, who are now tied with their tormentors with similar 1-1 records.
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