The exciting trio of Mike Cortez, Mark Cardona and Joseph Yeo delivered the killing blows as they combined for 15 of the Archers last 16 points and helped extend their unbeaten record this year to 4-0 against the 3-0 of archrival Ateneo.
"We were really tested by UST in this game but in spite of it, my players didnt lose their composure," said La Salle coach Franz Pumaren after his wards dealt the Tigers, winner of four straight titles starting in 1993, their second loss in four games.
The Archers trailed, 65-67, with six minutes left when Cortez, Cardona and Yeo caught fire while the rest of their teammates tightened their defense of Santo Tomas gunners Cyrus Baguio and Niño Gelig.
Earlier, University of the East turned back National University, 79-75, for its second straight victory after two consecutive losses.
The loss was the fourth in as many outings for the Bulldogs.
James Yap led the Warriors with 17 points while Arnold Booker chipped in 14 as Ronald Tubid struggled with six. points. Alfie Grijaldo tried to carry the load for the Bulldogs with his 18 points but simply ran out of steam in the end.