Starting from the 10th tee, Singh rode on a hot putter as he turned in 29 highlighted by five straight birdies from the 14th hole at the scenic Taman Dayu Golf Club and Resort.
Singh's two-day total of 17-under-par 127 was also a new record on the Asian Development Tour (ADT), replacing the previous record of 13-under-par 131 set by Siddikur at the 2011 Grameenphone Bangladesh Masters.
Local favourite Rory Hie returned with a 70 for 136 to lie in second place while Anura Rohana of Sri Lanka and Michael Moore of Australia were a further shot back in the US$75,000 ADT event.
Singh was blemish free in a round of nine birdies as he credited a hot putter for his incredible round.
"My putter was on fire on my first nine (started from the 10th tee) and after I holed my birdie putt just off the green on the 17th hole, I told myself I'm just going along for the ride and enjoy myself today [Thursday]. It was magical," said Singh, who was blemish free.
"I don't think I ever had a better round of putting in my life. I don't even know what score I shot until I submitted my card, so only God knows how many putts I made!"
Playing on a sponsor's invitation, Singh rewrote the one-day-old course record, which he set in the opening round, but he is still not thinking of a victory yet.
"The course is in amazing condition. I've had a hot week and great greens to back me up. You still can't think about the big "W", we have two more days to go and a long road ahead," said the 31-year-old, who is also an accomplished drummer.
Hie, the first Indonesian to earn an Asian Tour card in 2009, chipped in from 67 yards for an eagle two on the first hole and is not prepared to throw in the towel yet.
"It was bittersweet. I made a lot of good shots but couldn't capitalize on them because I couldn't read the green speeds. I left a couple of putts short out there. It could have been better but I'm still happy to be in second place.
"Anything can happen with a big lead. We've seen it before in professional tournaments. If I can play well, hopefully I can put pressure on him (Singh)," said Hie.
Australian Moore, who traded seven birdies against three bogeys for 68, will be on attack mode as he aims to cut Singh's vast lead.
"I'm going to have to be a little bit aggressive because of Singh's lead. I have to definitely hit it closer to the pins to try and find some birdies. I'm looking forward to it," said the 27-year-old, who is playing in his second season on the ADT.
"There are pins out there where you can't attack and there are some where you can so I'm going to wait for the opportunities and see how it unfolds," added Moore.
The halfway cut was set at two-over-par 146 with a total of 57 players qualifying for the last two rounds.