The match remained goalless for most of the time before Jaime Santos Colado finally broke the deadblock by curling in a free-kick in the 85th minute.
While East Bengal looked a little slippery in the defence, Army Red could not capitalise on the chances that came their way.
In the 24th minute, Army Red's Sushil Shah received a yellow card and just after three minutes, Alwin was shown another. A few seconds before half-time, Zothanpuia received the third yellow card for the Reds after a heavy tackle on Brandon Vanlalremdika.
The nail in the coffin came when Army Red's goalkeeper Muhammed Shanoos was shown a red card for trying to stop Bidyasagar Singh.
Incidentally, Bidyasagar Singh, who came in as a substitute, scored the second goal for East Bengal in stoppage time.