Joferson Gonzales sizzled with 14 points, including four straight in a 12-4 run that turned a shaky 52-49 lead into a 64-53 advantage with a little less than three minutes to go.
But the Altas refused to give up with Conrad Fritz Bauzon burying a couple of triples and Khiel Misa sinking one trey as Perpetual Help countered with its own 9-0 binge to close to the gap at 62-64, 51.6 seconds remaining in the contest.
However, the Cardinals toughened up on defense and held the Altas scoreless the rest of the way while scoring three points to clinch the victory, their fourth in a row.
"We’re really happy where we are right now because this is the school’s best start after a long while," said Mapua coach Horacio Lim.
In the other game, Gabby Espinas exploded with season-high 27 points and 18 rebounds as the defending champion Philippine Christian University Dolphins smashed the Jose Rizal Heavy Bombers, 68-51, to likewise grab a share of the lead.
It was the Bombers’ fourth loss in a row.
Raymond Tiongco added 11 points while rookie Kelvin dela Pena, who played high school ball in Calgary, Canada, and Neil Pascual combined for 18 points, 20 rebounds, seven assists and four steals.
The loss was Perpetual’s fourth straight.
Behind a pressure defense that anchored their first three wins, the Cardinals raced to a couple of 15-point leads in the first half and threatened to rip the game apart midway in the third period when Gonzales knocked in a triple for a 44-27 spread.
But a triple by rookie Josef Racho ignited a series of slow but effective runs by Perpetual bridging the last two quarters as the Altas rallied to close to within three, 49-52, early in the final quarter.
Tiongco countered by draining a long trey, sparking another Mapua run that gave the Cardinals another double-digit lead.