The man, aged in his 40s, was found with serious injuries in Caister Drive, Basildon, at about 21:30 on Tuesday.
The victim, who lived in the town, is thought to have been stabbed during an altercation with a group of about five youths or young men.
He was treated at the scene before being taken to Basildon Hospital where he died from his injuries.
Carole Crisp, 56, who lives nearby, has described the moment the injured man rang her doorbell, desperate for help.
"He buzzed my intercom, I never answered, he buzzed again. He said 'Can you help me, I've been stabbed'," she told BBC News.
Mrs Crisp said she cut off the man's clothes while her neighbour, a paramedic, tried to treat him before he was taken to hospital, where he died.
"I'm heartbroken for him and I'm heartbroken for his family," Mrs Crisp said.
Det Ch Insp Simon Werrett from Essex Police appealed for anyone who saw the attack to contact his team.
"This happened in a residential area so people would have been about," he said.
A murder investigation has begun after a man died following a stabbing in Essex, police have said.