The 22-year-old Priyanshu (72-70-70), the overnight leader by three shots, further built on his lead with a second successive round of 2-under-70 that moved his total to 4-under-212.
Delhi's Wasim Khan (74-71-71), last year's PGTI Qualifying School champion, was placed second at even-par-216.
Priyanshu came up with a flawless round and his two birdies on the 7th and 15th came as a result of conversions from a range of 16 to 20 feet.
The professional from the DLF Golf and Country Club in Gurugram, the only player in the field to have not shot a single over-par round so far, also made two brilliant par-saves on the 14th and 17th where he recovered well from the trees and hazard respectively.
Wasim marginally improved from overnight tied second to sole second thanks to his 71 on Wednesday.
Mumbai's Anil Bajrang Mane (72) occupied third position at 2-over-218.