Needing 472 for victory, Bengal folded up for 339 to give Mumbai a well deserved win on the fourth day in the Elite Division final.
Mumbai raced to their victory, taking the last six wickets for just five runs as the hosts scripted a superb comeback this season, winning the trophy after losing their first three matches of the league and being in danger of being relegated to the plate division.
The hosts rose like a phoenix, winning their last five matches including the final with a day to spare.
Set a target of 472 for a win, Bengal were kept in the run chase, with magnificent innings from Manoj Tiwari and Sourav Ganguly.
Beginning the fourth day at 98 for two with Deep Dasgupta and Manoj Tiwari at the crease, it looked like it was only a matter of time, Mumbai would get their hands on the coveted trophy.
However, the Bengal batsmen had other ideas and instead of going into their shell, they attacked whenever the opportunity presented them and kept the scoreboard moving, trying to put the pressure back on Mumbai.
Deep Dasgupta, who was 43 overnight, completed his half century in 115 balls with six boundaries. He was out soon after for 57, edging one from Wilkin Mota to the keeper Vinayak Samant, who completed a regulation catch. Bengal were then 153 for three.
Ganguly then joined youngster Manoj Tiwari and the two took the attack to the Mumbai bowlers scoring at four runs an over as both did not waste any time in punishing the loose balls.
Tiwari, infact, took a liking of the off spinner Ramesh Powar hitting the stocky bowler for two huge sixers as he raced to his 50 in just 84 balls with the help of seven boundaries and two sixes.
Ganguly, at the other end, was also batting beautifully as his off-side shots coming out from the middle of the bat and he brought up his 50 in 76 balls which included seven boundaries.
Tiwari enjoyed a bit of luck with Mumbai captain Amol Muzumdar dropping him in the slips when he was on 76 and 80, with Abhishek Nair suffering on both ocassions. Nair, however, finally got his man when Tiwari tried to cut him but only managed to give an easy catch to point where Rohit Sharma made no mistake as the Bengal youngster was out six short of a deserved 100. The two had put on 117 runs for the fourth wicket in only 176 balls with Bengal score reading 270 for four.
Rohan Gavaskar, the next man in, was in an attacking mood as he hit Zaheer Khan for three boundaries in one over and then followed it up with a superb straight drive of Agarkar.
However, the second new ball taken in the 85th over did the trick as Agarkar after being hit for a four got his revenge when he had Rohan Gavaskar playing a loose shot outside the off stump with Sahil Kukreja coming up with a brilliant catch at second slip. Gavaskar made 46 in just 49 balls with eight boundaries. Bengal at this stage were on 5 for 334 but the remaining wickets fell like wine pins.
In the next over, Zaheer Khan got rid of Laxmi Ratan Shukla beating the bastman for pace and then trapped Sourashish Lahiri in front of the wicket to leave Bengal at 335 for seven.
However, till Ganguly was at the crease there was room for the faithful to hope that Bengal might pull off something sensational, but when he fell for 90- again to Zaheer - pulling and only managing to lob a high catch to Ramesh Powar at midwicket, Bengal was staring at defeat with 338 on the board. Ganguly's 90 came in a stay of 129 balls and was studded with eight boundaries.
The end came when Ashok Dinda attempted to heave Ajit Agarkar over the ropes and holed out to Abhishek Nair at point.
Zaheer ended with nine wickets for the match, four in the second and was easily the player who impressed the most.
Mumbai Ist innings 320 (Tendulkar 105, Jaffer 112; Randeb Bose 4 for 77) and 294 (Rohit Sharma 57, Jaffer 53, Tendulkar 43; R Bose 5 for 71) beat Bengal 143 (Manoj Tiwari 42, S Sarkar 25; Zaheer 5 for 40) and 339 (Tiwari 94, Ganguly 90, D Dasgupta 57, R Gavaskar 46; Zaheer Khan 4 for 119) by 132 runs.