Chiragh, whose first win on the Asian Tour came at his home course, Delhi Golf Club last year, had fellow Indian Rashid Khan (66) for company at the same position.
Himmat Rai (70-72) was tied-34th, while Jeev Milkha Singh (72-68), Gaganjeet Bhullar (72-68) and Arjun Atwal (68-72) were all tied at 49th spot.
SSP Chawrasia (68-76) and Shiv Kapur (72-74) missed the halfway cut.
Big-hitting Scott Hend equalled the course record of eight-under-par 64 to earn a share of the halfway lead with Sweden's Pelle Edberg at the True Thailand Classic.
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Both Chiragh and Rashid are from the Delhi Golf Club, where they play the Hero Indian Open next week.
"Obviously, it's been good. I've played some good golf the last two days. I've putted well, hit the ball well and planned my game pretty well. Everything is good so far," Chiragh said.
Talking of the conditions, he smiled and added: "Somehow I always seem to catch the wind. So it doesn't really matter if I'm playing morning or afternoon. But it was a lot hotter and humid too than yesterday. It was slightly less windy than yesterday which helped."
As for the Black Mountain course, he said, "I love this course. I've never played well here in the past, so it's a bonus that I'm playing well. But beautiful golf course and great facilities. Always a privilege to come out here to play."
Thailand's Panuphol Pittayarat charged into contention with a 65 in the USD 1.75 million event co-sanctioned by the Asian Tour and European Tour to lie one back while Black Mountain resident Simon Yates of Scotland, 2014 Asian Tour Order of Merit winner David Lipsky of the United States, South African Shaun Norris, Welshman Rhys Davies and overnight leader Peter Uihlein of the US were amongst those bunch on 135.