Assam-born player Alen Deory scored the only goal to give the north-eastern side all three points at the JL Nehru Stadium.
Deory found the net in the 78th minute of the match.
Hosts Shillong Lajong showed spark early on but it was Gokulam who had the first hit at the post through Chigozie's header off Alsaleh's flag-kick.
However, Shillong Lajong ended as the winners.