GAB Dagangon made the big plays for Perpetual Help down the stretch as it kept Letran winless in the Filoil Flying V Preseason Tournament with an 87-86 win in overtime on Friday afternoon in San Juan.
Dagangon scored 26 points, including the go-ahead jumper with 7.2 seconds to play.
The Knights had one more chance to win their first game in four tries but Jerrick Balanza lost the ball in the final possession to give the Altas the close win.
"Actually that's basketball. It's all about momentum. That's what I told my guys, that these guys will take the lead. We have to come back," said Perpetual head coach Nic Omorogbe.
"It's still a work in progress. We're just trying to put things together and get ready for the NCAA," he added.
GJ Ylagan added 17 points, making 5-of-11 three-pointers while AJ Coronel chipped in 11.
Keith Pido, Flash Sadiwa and Kervin Lucente all added eight each to give the Altas their first win in two games in the tournament.
Bong Quinto had 18 points, eight assists and six rebounds for the now 0-4 Knights who rested Rey Nambatac and JP Calvo.