Runners-up for the last two years, East Bengal ended their I-League campaign on a miserable note, going down to Shillong Lajong FC by a solitary goal at the Kalyani Stadium on Sunday.
Japanese forward Taisuke Matsugae struck the all-important goal in the eighth minute to give the Shillong outfit their first away victory that came in the concluding round of the I-League.
East Bengal finished third on the table with 47 points, while Lajong (28) ended their campaign at the 11th spot.
The win would be a big setback for Trevor Morgan's boys, who play their AFC Cup pre-quarterfinals against Yangon United at home in three days' time.
Dempo beat Salgaocar, finish fifth
Anthony Pereira's late goal helped Dempo edge Salgaocar 2-1 to finish fifth in the I-League played in Vasco on Sunday. Salgaocar, who were looking to finish sixth, started well and took the lead in the 15th minute through Gabriel Obatola.
Dempo retaliated and restored parity five minutes later through Ryuji Sueoka as both the teams went into the breather locked at 1-1.
The second half was fought evenly and the match was heading for a draw before Periera struck for Dempo in the 90th minute.
Nicolau Borges from the left, sent a long pass to Ryuji Sueoka, who in turn relayed the ball to Pereira, who scored to give Dempo the win after nine defeats in a row and end the season on a winning note.
Dempo, who took their tally to 40 points from 26 matches, finished fifth while Salgaocar remained at the seventh position with 33 points.