In their previous outings, IOC had trounced All India Customs and Central Excise (12-1) and drubbed Integral Coach Factory 15-3.
IOC will take on Air India on Thursday and have gained nine points so far to lead points table in Group-B, while both Indian Railways and Air India have three points each.
IOC led 1-0 at half time through Raghunath and then Deepak Thakur scored his first of the three goals but Railways reduced the margin in the 12th minute through Chingleng Sana. Then Deepak Thakur scored twice to help his team lead 4-1.
Railways' B Horo and Nitin Kumar found the target to reduce the margin but with just three minutes to go, Deepak slammed a peach of a goal to settle the issue.
Earlier, Customs defeated ICF 6-2 with Laxman Karan, son of Olympian Vasudevan Baskaran, scoring three goals. Abhishek Kumar Singh, Jayesh Jhadav, Nitin Thimayya were the other scorers.
For ICF, Gunasekaran and Shyam Kumar were the scorers.