Sanju, the Kolkata golfer, carded six birdies against a single bogey and is followed by Jaibir Singh, who struck four-under-par 68 in the Tk4.8m tournament.
With three-under-par 69, Indian golfers Rashid Khan and Khalin Joshi and Sri Lanka's Mithun Perera jointly share third place.
Zamal Hossain Mollah, Dulal Hossain and Robin Miah were the best Bangladesh golfers on display as the trio jointly share ninth position following their one-under-par 71.
Following the day's proceedings, Zamal said, “I couldn't play well. Swing and putting were off colour. Around four yards away from the hole, I wasn't able to connect at least seven shots. As a result, I missed a few birdies. Even then I hit four birdies. If it weren't for my three bogeys, I would've been in a much better position. This led to my downfall.
“Still, I am hopeful of becoming champion as there are still three rounds left. If I can give my best, I can finish at the top.”
Mohammad Sanju (India) -5 67
Jaibir Singh (India) -4 68
Rashid Khan (India) -3 69
Mithun Perera (SL) -3 69
Khalin Joshi (India) -3 69
Rabin Miah (Bangladesh) -1 71
Dulal Hossain (Bangladesh) -1 71
Zamal Hossain (Bangladesh) -1 71
Mohammad Ismail (Bangladesh) Par 72
Yassar Rahman (Bangladesh) Par 72