Shamim's total stands at six-under-138 at the halfway stage of the tournament.
Mukesh Kumar of Mhow shot a 71 to be placed one stroke behind the leader in second position.
Shamim (70-68), who was overnight tied fifth, dropped a bogey early in his round after his tee shot found the rough on the third hole.
The 38-year-old, currently placed second on the Rolex Rankings, soon turned the tide with eagle-birdie on the next two holes.
Shamim eagled the par-5 fourth after hitting the green in two shots and subsequently converting the six feet putt. He then sank a 20-footer to birdie the fifth.
Shamim, a three-time winner in the current PGTI season, conceded a bogey on the sixth but came back fighting with a sublime effort on the back-nine where he birdied the 13th, 16th and 17th. He sank a monstrous 35-feet putt on the 13th and chipped-in from behind the green on the 17th.
"I missed just two fairways today as I drove it really well. My putting was also much better as compared to round one. I sank some long putts. One has to be aggressive on this course since it is quite long," said Shamim.
"The next two rounds are very crucial in the context of the Rolex Rankings race as well. The difference between Rashid Khan and myself is just over Rs 11,000 in the rankings. If I finish even one position ahead of him I would overtake him to become number one," he added. MORE
