Boyet Bautista came away with 19 points in another fiery stint he highlighted with five triples while Aaron Aban tossed in 17 points for the Knights, who moved within a victory from sweeping the first round elims.
Kelvin dela Peña, noted for hitting buzzer-beating shots in the PBL, couldn’t make one this time as he muffed a potential game-tying trey at the buzzer.
"We made the necessary stops, that’s one of the keys," said Letran coach Louie Alas, who steered the Muralla-based school’s title romps in 1998, 2003 and 2005.
The win also gave Letran the momentum and confidence it needs when it plays second-running San Beda, the other streaking squad on a four-game run and a 5-1 record, on Wednesday in what many believe would be a preview of this year’s championship.
"It would be a tough match because San Beda is the best defensive team in the league right now," said Alas.
Employing a combination of sleek running game and pesky full-court defense, the Knights controlled the tempo early and built leads of as many as 20, 41-21, in the second quarter.
But Letran came out of the half a disorganized lot, falling into a maze of errors and poor shot selections, enabling Mapua to strike back before eventually seizing the lead at 71-68 lead behind dela Peña and Jerby del Rosario.
However, the Knights clamped down on defense while Andro Quinday stepped up and nailed four foul shots in a 6-0 windup that sealed the victory for Letran.
Mapua fell to 3-3.
Earlier, Philippine Christian U imposed its will underneath as it downed St. Benilde, 66-61, to close its stint in the first round with a 5-2 (win-loss) slate.
Gabby Espinas scored 15 points, pulled down 14 rebounds and had four shot blocks while Ian Garrido and Beau Belga combined for 12 points and 14 boards to power the Dolphins to the victory.
St. Benilde absorbed its sixth setback against a triumph.