The Delhi golfer carded four-under-68 in round four to end up with a tournament total of nine-under-279.
Bangalore's R Murthy finished runner-up at eight- under-280.
Shamim (69-71-71-68), who was three off the lead in tied fourth position after round three, made five birdies against a lone bogey in the final round. Shamim started the day confidently by sinking a 30-footer for birdie on the second.
He followed that up with another superb putt from 20 feet that earned him a birdie on the fourth.
Finding the hazard on the ninth proved to be costly for Shamim as he ended up dropping a bogey on that hole.
The 34-year-old Shamim surged ahead of the rest of the field with three consecutive birdies on the 13th, 14th and 15th. He landed it within four feet on the 14th and 15th. Shamim made pars on the remaining three holes to ensure victory. Shamim, the only player to shoot four sub-par rounds this week, has now climbed from third place to second on the Rolex Rankings.
Shamim said, "It's quite satisfying to bag a second title in the season. I missed a lot of short putts earlier this week but managed to convert most of them today. The long putts at the start of the round gave me a lot of confidence."
R Murthy (71-70-72-67) shot the best score of the day, a five-under-67, to end up in second place, one shot behind the winner.
His final round featured eight birdies and three bogeys.
Delhi's Ashok Kumar and Noida's Gaurav Pratap Singh shared third place at six-under-282.
Gurgaon's Shubhankar Sharma won the trophy for the best performance by an amateur. He was the highest-placed amateur in the field at tied ninth position with a total score of three-under-285.
