Lahiri is now 16-under and one shot ahead of Thaworn Wiratchant, a 17-time Asian Tour winner. Wiratchant carded a flawless 66 to take second place while Australia's Andrew Dodt gate crashed the home party by sharing third place with three other Thai players Sutijet Kooratanapisan, Panuphol Pittayarat and Jakraphan Premsirigorn at the Singha Park Khon Kaen Golf Club.
SSP Chowrasia, the co-leader after first round, further slipped to tied 12th as he shot two-under 70 to come to -10 after three rounds, while Arjun Atwal (72-67-72) was tied 25th at six-under and Rashid Khan (71-69-71) was five-under 211 in tied 37th place.
Lahiri, who led from the opening day, surprised even himself after returning to find himself back atop the leaderboard. The 27-year-old struggled early in his round as he turned in 36, with just one having one birdie which was offset by a bogey-four on the fifth hole.
"I'm actually surprised to find myself in the lead as I didn't play well today especially on the front-nine. It was quite a struggle there. It felt like every step I took, I took two steps back again," said Lahiri, who has already won at CIMB Niaga Indonesian Masters and Venetian Macau Open this year.
"I knew Thaworn was off to a hot start and I was struggling on the front-nine. I was just trying to catch up and stay ahead. So it was really nice to finish off with an eagle as I really needed that boost," said Lahiri.