Mohun Bagan defeated Bengaluru FC 3-1 in their AFC Cup encounter at the Rabindra Sarobas stadium to put the Blues in the position of having to win their last group game against Maziya to make the inter-zonal matches.
Goals from Jeje Lalpekhlua, Kean Lewis and Bikramjit Singh helped the Mariners get the win in their Group E AFC Cup encounter.
The result leaves Mohun Bagan with six points as they have no chance of progressing through to the next round. Bengaluru, on the other hand, are second in the group with nine points.
Their last match is against group leaders Maziya, who have 12 points and they will need the match to go in their favour with them winning, as only the group winners move to the next round.
A win would help the Jindal-owned outfit to go through to the next round, as they will be tied on points at the top with the Maldives-based team, but will qualify because of their superior head-to-head record.
Albert Roca rested many of his first-team regulars with one eye on the Federation Cup final against Bagan on Sunday, as he played a young team.
The Kolkata outfit took full advantage and ensured they showed their superiority early. Raynier Fernandes' chip over the defense found Jeje, who made no mistake and finished past Lalthuammawia Ralte in goal.
The team from Bengaluru then had a good chance through Seminlen Doungel, who was set up well by CK Vineeth, held off two defenders, before seeing his shot saved by Shilton Paul.
Doungel then leveled matters in the encounter, scoring in the 52nd minute to make it 1-1. However, the Kolkata outfit then put matters beyond any doubt, scoring through Kean Lewis' deflected effort, with Bikramjit Singh then making it 3-1.