Police found the man in Blackshots Lane, Grays, at about 00:35 BST. The 24-year-old from Stanford-Le-Hope had been stabbed in the chest.
Officers had been called to reports of men fighting, Essex Police have confirmed.
Two men, aged 22 and 21, have been arrested on suspicion of murder.
Police said the three injured men are being treated at Basildon Hospital with stomach and chest wounds.
It is believed the incident is related to another in nearby Chafford Hundred.
In that incident, an 18-year-old was knocked unconscious on Fleming Road at about 01:55 BST.
He was taken to hospital for treatment and later arrested on suspicion of murder in connection with the killing in Grays, police said.

Paul Massey was shot five times outside his Salford home on 26 July 2015 in what police believe to be a gang feud.
No-one has been arrested over the killing of the 55-year-old security boss, who was jailed for 14 years in 1999 for stabbing a man outside a club.
A full inquest is expected after police complete their criminal investigation.
The victim's partner, eight other members of his family and detectives attended Bolton Coroner's Court for a brief pre-inquest hearing.
Jennifer Leeming, senior coroner for Manchester West, asked the senior officer in the case: "I understand these inquiries, the inquiries touching on the death of Mr Massey, are still active inquiries and I understand that there's reason to suppose that charges will result, is that right?"
Det Supt Howard Millington, of Greater Manchester Police, replied: "That's right. We are still providing evidence to the CPS (Crown Prosecution Service)."
Massey was dubbed Mr Big by the late Salford councillor Joe Burrows at a town hall meeting to discuss civil disturbances in 1992.
He was jailed in 1999 for 14 years after he stabbed a man in the groin outside a club in Manchester, severing an artery.
He was a well-known figure in his home city of Salford and had been involved with security firms operating in Manchester and beyond.
A Â£50,000 reward is still on offer for information leading to the arrest and conviction of the killers.
A further pre-inquest hearing was scheduled for 17 May.
A man was stabbed to death and three others suffered "life-threatening injuries" during a disturbance in Essex.
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Detectives are still gathering evidence into the death of a convicted criminal once branded "Mr Big", a pre-inquest hearing has heard.