Julian Perico of Peru ran off four straight birdies early on the back nine Friday and closed with another for a 6-under 66, giving him a three-shot lead and the 36-hole scoring record at the Latin America Amateur Championship.
Segundo Oliva Pinto of Argentina also made a big run on the back nine of Teeth of the Dog at Casa de Campo, only that was atone to his rough start in the second round when he had three bogeys on the opening four holes and failed to birdie the par-5 second.
Oliva Pinto salvaged a 72.
Two other Argentines, defending champion Abel Gallegos (69) and Vicente Mazilio (71), were four shots behind.