India 'A' will now clash for the title with Sri Lanka 'A', who made it to the title round as the second placed team garnering 11 points, seven less than the hosts. Pakistan finished on seven points.
Electing to bat first after the entire morning session was lost due to rains, which reduced the match to a 25-over-a-side affair, Pakistan failed to negotiate the Indian bowlers who bowled well in overcast conditions and fell victim to poor shots to be skittled out for 97 in 22.2 overs.
In reply, the hosts overcame a mid-innings slump to reach 99 for six in 22.2 overs, leading to celebrations among the around 30,000 spectators at the Eden Gardens on Sunday.
Pakistan's young pacer Junaid Zia (three for 12) triggered the collapse in the Indian innings picking up three wickets, including two in one over, to reduce the hosts to 69 for six in the 16th over.
But Mongia (48 not out) and Bahutule (8 not out) prevented any further damage to see India through with 16 balls to spare.
India seemed comfortably placed at 52 for one with Yuvraj Singh and Dinesh Mongia in the middle, when the drama, so characteristic of the glorious game of cricket, began.
The dashing Yuvraj, who struck three exquisite boundaries, was foxed by a delivery from off-spinner Muhammad Hafeez which turned viciously and wicketkeeper Amin-ur-Rehman removed the bails in a flash, with the batsman out of the crease.
Leggie Mansoor Amjad then saw the back of India 'A' skipper Badani (0) as the home side became 64 for three before Zia, who bowled at a searing pace in the bowler-friendly conditions, took centre-stage, taking wickets of consecutive balls in his fourth over.
The shaven-headed Zia first bowled Sanjay Bangar (0) with a low delivery, before getting Rohan Gavaskar (0) plumb leg-before to be on a hat-trick. But the Pakistani missed the personal feat, bowling the next delivery wide outside the off-stump to cause no trouble to Ajay Ratra.
He struck a further blow, removing Ratra (2) with the last ball of his next over. The ball was virtually unplayable, as it pitched outside the off- stump, and cut sharply in to dislodge the wicket-keeper batsman's bails.
But Mongia, who came as an opener and looked shaky in the beginning, gained in confidence as overs went by, and played without much fuss to bring India 'A' slowly closer to victory.
He eased the pressure by dispatching Hafeez for a six over mid-wicket in the 20th over to take India to 89, before Bahutule got the winning runs of pacer Muhammad Khalil with a boundary past long-off.
Earlier, only four of the Pakistan batsmen reached double figures, with Bilal Asad (23) being the top scorer on a difficult wicket.
The visitors, who were needed to win this match with a bonus point to pip Sri Lanka in the race for a place in the final, also did no good to their cause by playing some reckless shots.
The visitors innings got off to a shaky start when skipper Shahid Afridi (0) went for a needless slog in the very fourth over of the innings bowled by Siddharth Trivedi and ballooned a catch to Hemang Badani at widish mid-on.
Wicketkeeper batsman Amin-ur Rehman (10), promoted in the batting order, also did not last long, departing in the sixth over when he was castled by Munaf Patel.
Left-arm spinner Dinesh Mongia then picked up Muhammad Haffez (5) before Pakistan's 50 was posted in 10.2 overs. But Sanjay Bangar struck a double blow in the same over to leave the visitors tottering at 52 for five. The Railway medium pacer first ended the innings of Salman Butt (21) when the latter went for a cut and was caught at point by Yuvraj Singh. Three balls later, in-form batsman Navid Latif (1) was trapped leg-before.
Faisal Iqbal (10) fell cheaply before Asad tried to stem the rot in the company of the tailenders. However, he misread a Sairaj Bahutule delivery and Ajay Ratra did a smart bit of stumping.
Pak beat SL to stay in hunt for final berth