The Red Warriors overcame the absence of their key players to thwart Adamson, 78-70, while the Stags downed Jose Rizal University, 73-68, at the Trinity University of Asia gym in Quezon City.
UE and San Sebastian will shoot for the crown on Monday.
Charles Mammie filled the void left by Mustapha Arafat with 21 points.
Jason Pusiquit shot 18 points while Jaymar Perez and Bradwin Guinto had 15 apiece for the Stags.
In the juniors division, Carlo Young and Jason Jimenez scored 15 and 13 points respectively to lead Chiang Kai Shek to a 65-59 win over San Beda.
The Dragons moved on to finals and will face Hope Christian School, which drew 21 points from Job Go in its semis win over Xavier School, 73-62.
UE blew an early double-digit lead as the Falcons pulled to within three, 36-39, at one point in the third quarter.
But Ralph Olivarez and Gino Jumao-as, who pumped in 15 points, came through to help keep JRU at bay. A triple from Olivarez before a drive by Jumao-as stretched their lead back to nine, 56-47, entering the fourth period.
Mammie teamed up with Desmond Berestain and Renz Palma as the Warriors got off to a strong start to lead, 23-6, in the first quarter.