While Parvez Rasool's prediction of restricting West Indies A to around 300 failed as the visitors reached 429 in their first innings, even India A's top three - KL Rahul, Jiwanjot Singh and Cheteshwar Pujara - fell cheaply to give Windies an advantage.
Gambhir cashed in after the initial quiet period when spinners were introduced. Nathan Lyon, Xavier Doherty and rookie spinner Ashton Agar, all went for plenty as the left-hander proved why he is one of the best players of spin around.
For the visitors, pacer Siddharth Kaul and spinner Sarabjit Singh bagged four wickets apiece while skipper Harbhajan Singh had to content with only one wicket.
Bengal face an uphill battle now with just another 98 runs to defend and still nine wickets in hand for Punjab.