The other two matches ended in draws as ONGC managed to spilt points with Punjab National Bank with a 3-3 result while former champions Army XI drew 3-3 with BPCL in Group-A.
IOC's VR Raghunath scored in the ninth minute and then Deepak Thakur came up with a brace to start the rout of the rivals.
Every IOC player, except goal keeper Devesh Chauhan, contributed in team's win.
VR Raghunath (7, 19), Deepak Thakur (11, 12, 69), Thimmana (34), Vikas Sharma (37), Vikram Kanth (43), Prabhjot Singh (44, 47), Dharamveer Singh (46), Sunil Yadav (50), Roshan Minz (53, 63), Didar Singh 60) were the scores for IOC, while M Iyappan, (15, 24) and S Vivek (66) were successful for ICF.
Earlier, Sunil Ekka (6th and 21st) and Muthanna (51st) scored for Army.