On 25 January 1948, Sepoy Man Singh was in a picquet in Poonch in the J & K Sector when it was very strongly attacked by the enemy more than two hundred strong. His platoon was holding the front sector of the key defensive position. They approached close to the picquet perimeter covered by their six LMGs and grenade discharges firing heavily from a distance of about 400 yards. Sepoy Man Singh's platoon had suffered about 50 per cent casualties and the enemy was going to rush in at any moment.

Sepoy Marl Singh, on his own initiative, came out of his slit trench and ran forward engaging the enemy with grenades and eventually succeeded in silencing two of the enemy LMGs. In the meantime, a burst of LMG fire hit him on his head. In spite of the mortal wound sustained by him, he fired another grenade saying, "I'm finished but I will finish you too", and thus smashed another enemy LMG with its accompanying numbers. This gallant action of Sepoy Man Singh at the cost of his own life, which set an example of bravery and devotion to duty, saved a terrible loss of lives to his company and helped in protection of the Poonch Garrison.