Manoj Kumar Sharma, who worked as a technician for Indigo airlines, was returning home at around 10 PM last night when the incident happened.
"Eyewitnesses said that when he reached lane number 41 he saw some miscreants eve teasing a girl, he stopped and tried to intervene and reason with them. One of them took out a knife and stabbed him in his abdomen and fled from the spot," said a police official.
Sharma is survived by wife and a 11-year-old son.
In another incident reported from East Delhi's Shakarpur area, a 35-year-old man was found dead with stab injuries near school block last night.
The deceased has been identified as Suraj, a TSR driver and a resident of the same block. Preliminary investigations revealed that the incident is a result of personal enmity between friends.
Investigations have thrown up the name of one youth called Sonu and police has launched a manhunt to nab him, police said.