MANILA -- Justin Quiban stormed past Reymon Jaraula and Jhonnel Ababa for a one-stroke after the second day of the ICTSI Del Monte Championship, Wednesday in Bukidnon.

First-round leader Clyde Mondilla wrestled with his putter after grabbing the lead on Tuesday, and Quiban stuck to his game plan for a five-under 67 card that pushed him to the top of the field.

"It's pretty much the same," said Quiban of his performance midway through the competition. "I was just trying to stick to my strategies. It’s a tight course so I need to hit the fairways and try to capitalize on the par-5s."

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He birdied all but one of the four long holes, including the last on No. 9 that moved him past Jaraula and Ababa.

Mondilla later rued his poor putting that led to a number of missed chances. He fell to solo fourth with a 136, while Rupert Zaragosa settled for an even-par to likewise drop to fifth at 137.

"I hit an errant drive and missed a four-footer for par for my bogeys on Nos. 16 and 1, so my putting really didn't click," said Mondilla, seeking to score a follow-up to his victory at Forest Hills last June. "Lamang talaga ang magaling mag-putt dito."

In the women's side, Velinda Castil birdied two of the last four holes for a second straight 73 that kept her on top of the leaderboard.

Castil’s birdies on Nos. 15 and 18 made up for her double-bogey on the first hole and a bogey on the ninth. In contrast, Harmie Constantino and Daniella Uy limped with mishaps on Del Monte Golf Club’s tough finishing holes and fell off the leaderboard.

Castil now has an aggregate of 146 and a one-shot lead over Pamela Mariano.

"Medyo kinakabahan ako kasi 1-up lang ang lamang ko," the 15-year-old Castil said. "Sana lang, bukas ma-maintain ko lang ang score ko."

Castil has a chance to become the youngest – and the first junior golfer – to win on the Ladies Philippine Golf Tour. Princess Superal was 16 when she won the final leg of the LPGT’s inaugural season in Baguio in 2013.