Dempo striker R C Prakash missed a crucial penalty as National Football League champions East Bengal scored a 3-0 victory over the Goa side and set up a semi-final meeting with Air India, who drew 1-1 with Vasco FC, in the Durand Cup football tournament in Delhi on Thursday.
Requiring just a draw to advance, Dempo held the defending champions goalless till the 51st minute when Mike Okoro put the Kolkatans ahead, but wasted a golden opportunity to draw level two minutes later when Prakash blasted a penalty kick wide.
East Bengal then survived several attacks by the Goans before Malsawmtluanga (81st minute) and K Kulothungan (89th) put the match beyond the reach of Dempo.
Earlier in the day, Air India came back from a 12th minute goal by Dennis Cabral and equalised through Suprit Jathanna in the 56th minute to send Vasco to second place in Group D.
East Bengal and Air India, the two group winners, will now clash in the second semi-final on Saturday after Salgaocar meets Mahindra United tomorrow in the first semi-final.
In what was the best match so far in the 116th edition of the tournament, Dempo matched East Bengal move for move. Till they faded away in the last ten minutes, the Goa team held the edge over their famed Kolkata opponents, which had India's top player Baichung Bhutia in their eleven.