While Dharma posted a four-under-67 in round three, Zamal came up with a two-under-69 as both players ended up with a three-day tally of 11-under-203.
Jamshedpur-based amateur Karan Taunk was placed third at nine-under-205.
M Dharma (66-70-67) fired a bogey-free 67 to climb from overnight tied second to joint first. Dharma made a birdie on first hole for the third straight day with a 10 feet conversion.
He made it two birdies in a row with a brilliant chip on the second that stopped three feet from the hole.
Md Zamal Hossain Mollah (70-64-69), the overnight leader, made four birdies and two bogeys for a 69 that kept him at the top of the pack along with Dharma. Mollah's chip on the second set up a tap-in for birdie.
The 28-year-old left himself birdie putts from six feet and less on the sixth, 13th and 17th, thanks to his excellent iron-play.
Gurgaon's Shubhankar Sharma, Gaurav Pratap Singh of Noida and Delhi's Manav Jaini were in tied fourth position at seven-under-207.
Defending champion Mithun Perera of Sri Lanka was placed tied 10th at four-under-210.
The entire field comprising the 61 players who made the cut, played nine holes each on both courses, Beldih and Golmuri.
Thirty-three golfers with the best scores at the end of round two teed off from Golmuri and finished at Beldih.