Letran opened its own campaign in the tourney with a 69-64 victory over San Beda.
Getting off to a hot start was College of St. Benilde, the 2000 champion which broke loose in the third period to beat last year’s losing finalist Jose Rizal University, 82-67.
The Cardinals got off to a slow start and faced an 11-30 second-quarter deficit against the Dolphins, who created some ripples last year when they almost made it to the Final Four.
Erwin Sta. Maria anchored the Cardinals’ big comeback in the final half. He scored seven of his team-high 18 points in the fourth quarter, including three free throws in the dying seconds.
"PCU is a strong team with a lot of offensive arsenal," said Mapua coach Horacio Lim, out to steer the team to the title it last won in 1990 and 1991 under Joel Banal. "But we showed a lot of endgame character."
The Dolphins, now being handled by ex-Olympian Jimmy Mariano, caught almost everybody by surprise when they raced to the early lead behind the hot hands of Loreto Soriano who exploded with 15 points in the opening quarter alone.
But the Cardinals refused to be cowed as they slowly clawed back into the contest, trimming the deficit to 28-40 at the half and even closer at 51-55 entering the final period.
Soriano, who finished with 28 points, hit his sixth and last triple for the game to tie the count at 67. Mapua skipper Robert Lagar then drilled in back-to-back baskets while Sta. Maria delivered from the stripe for a decisive 7-1 windup.