The Baby Tamaraws dislodged the Bullpups on the top of the table with 17 points with a match left in the elimination round.
NU finished its elimination round stint with 16 points in second place following a goalless draw with University of Santo Tomas in the other match at the FEU-Diliman pitch.
The Bullpups are making their first-ever championship stint.
Pocholo Bugas and Kart Talaroc scored twice, while Marc Tobias and Andrei Sabejoh also the back of the net for the Baby Tamaraws.
Gunning for a record ninth straight title, FEU-Diliman will face NU in the one-game Final. The schedule will be announced later.
The Tiger Cubs moved up to five points while the Junior Archers remained without a point.
The final elimination round matchday fixtures on Sunday starting at 1 p.m. will have UST taking on De La Salle-Zobel, and FEU-Diliman battling Ateneo.