Shamim's overall score is 11-under-199.
Rashid Khan, another Delhi golfer, is placed second as he trailed Shamim by one stroke going into the final day of the Rs 1 crore prize money tournament at the Bombay Presidency Golf Club in suburban Chembur.
Vinod Kumar (69-65-67) of Delhi made a move from overnight tied fourth to tied third after a round of 67 today.
Chandigarh's Harendra Gupta (65-66-70), the round two leader, slipped to tied third in round three after returning an even-par-70 that included three birdies and three bogeys. Kolkata's SSP Chowrasia lies fifth at seven-under-203.
Shamim (65-68-66), who was tied second overnight, enjoyed a good start on the day as he picked up a birdie on the first.
However, a couple of missed chip-putts led to bogeys for Shamim on the second and seventh before a brilliant 10-feet birdie putt on the par-3 eighth got him back to level-par.
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From there on, the 34-year-old made further progress with birdies on the 11th and 16th and a spectacular eagle on the 18th. He sank a 25-footer on the 11th and a 20-footer on the 18th, which gave him the lead.
Shamim, the current Rolex Rankings leader, said, "I had a brilliant day with the putter. I got my rhythm going after the 10-feet birdie putt on the eighth. Unlike round two, I putted really well on the back-nine today.
"The 20-feet eagle putt on the closing 18th helped me finish the day as the leader and did a lot for my confidence going into the final round. That putt was a tricky one as the ball had to travel first uphill and then downhill."
Rashid (69-65-66), moved up from overnight tied fourth to second place after posting a 66 today. He got off to a flying start in round three with birdies on the first, second and fourth holes. (More)