The 31-year-old Sinfuegos superb short game and a few incredible recoveries saved him from what could have been a disastrous stint at his home course, riding on a three-birdie blitzkrieg from the second hole to grab the upperhand.
A smiling Sinfuego shook his head in disbelief seeing his name at the top of the standings, knowing he could have easily joined the second round cut-off casualties that included debuting pro Angelo Que if not for the big breaks.
Sinfuegos 139 aggregate for 36 holes gave him a one-stroke lead over first round co-leader Robert Pactolerin, Mars Pucay and Danny Zarate with 11 others well just four strokes or less to set the stage for a mad dash to the P100,000 champions purse offered in the tourney presented by San Miguel Beer.
Pucay and Zarate, partners for the World Cup qualifying last month in Malaysia, fired similar 68s. Pactolerin relinquished the lead after he made three consecutive bogeys from the 16th en route to a 72.
Streaks were the order of the day as Zarate spiked his round with five birdies in a row from the fifth.
Rodrigo Cuello collected seven birdies in shooting the days best of 67 that put him at 141, a stroke ahead of second leg winner Cassius Casas (70), Benjie Magada (71), Vic Santia (70) and Ruben Sasutil (70).
And as the big guns exploded, Que went home with a battered pride after missing the cut by a mere stroke right in his pro debut. The national team star returned a 73 for a 148 in a big letdown after proving himself to be among the worlds best in his farewell stint in Malaysia.
"Hindi ako makapaniwala na natapos akong walang bogey, sa sama ng palo pa-cutoff talaga iyon. Milagro na lang," said Sinfuego who went straight home and skipped his usual driving range shots after his round.
Sinfuego won his first and only title last year in the Camp John Hay leg of the MRT Tour. He kept himself busy during the long lull by joining members of Canlubangs amateur stable in practice.
The sore back limiting him to just a half swing, Sinfuego missed the first four greens in the back nine where he started but still made pars.
On the par-5 second hole, another bad swing hit a coconut tree and left him hitting his second shot from the ladies tee. He got onto the fairway with a 3-wood before slamming another unbelievable 3-wood approach that set him up for a three-foot birdie.
That set the tone for his three-birdie barrage where he made a four-footer on the tough third hole and another from the same distance on the treacherous No. 3 off a 6-iron tee-shot.