Mohun Bagan, facing a must-win situation, failed to cash in on their numerical advantage and finished goalless against arch-rivals East Bengal in a keenly-contested Super Six round match of the Kolkata Super Division football league on Thursday.

Needing a victory to remain in the fray for the title, Bagan had their task made easier as two of East Bengal's key players -- Deepak Mondal and Debjit Ghosh -- were given marching orders by referee Subrata Sarkar in the high-pitched battle at the flood-lit Salt Lake stadium.

Bagan, who also saw their new recruit Lolendra Singh pick up a red card in the opening half, tried their level best to capitalise on the numerical advantage but were done in by lack of thrust and poor finishing by their strikers as also the resolute defending by Mahesh Gawli and M Suresh.

With this draw, defending champions East Bengal remain at the top with a five-point difference over Bagan.

East Bengal, who were handicapped by the absence of star striker Baichung Bhutia, Alvito D'Cunha and skipper Suley Musah, matched Bagan for most of the match and could even have won the tie but for an easy miss by Nigerian Mike Okoro in the early stages.

The initial aggression of the red and gold brigade, however, received a jolt after the referee sent off their reliable defender Mondal and Bagan's Lolendra for indulging in a scuffle in the 25th minute.

Dealing a further blow to his side, Debjit Ghosh picked up his second yellow card of the match early into the second half, reducing East Bengal to nine men.

Bagan, who failed to penetrate the compact East Bengal citadel in the initial stages, stepped up their attack with skipper Renedy Singh and Brazilian duo Jose Barreto and Marcos Pereira toiling hard to utilise the opportunity.

A combined move by Barreto and Renedy offered an easy chance for Marcos in the 60th minute, but he shot wide. The Brazilian earlier, in the opening session, wasted a fine Barreto pass from inside the box.

In the 65th minute, Mehtab Hossain failed to convert a measured pass from Marcos before Barreto created some positive moves but to no avail.

East Bengal also had their share of chances. In the eighth minute, youngster MalswamTluanga laid a nice ball for an advancing Okoro, whose right footer from inside the box went wide.

Bagan goalkeeper Prosanto Dora, who had a good day under the bar, came to the rescue of his side on a number of occasions.

East Bengal medio Douglas da Silva, who failed to convert a Sur Kumar floater in the 31st minute, narrowly missed the target from a free-kick late into the game.