He has been named as 35-year-old Nathaniel Ago.
Four men, aged between 17 and 43-years-old, have been arrested on suspicion of murder.
A 17-year-old male, 22-year-old man and 25-year-old man were arrested on Tuesday, 8 June.
A 43-year-old man was arrested in the early hours of Wednesday, 9 June.
They have been taken into custody at police stations in south London.
On Wednesday, 2 June, police were called at 4.23pm to reports of men fighting in the street.
A man, aged in his mid-30s, was found at the scene with knife wounds. Detectives have now identified him as 35-year-old Nathaniel Ago. He was taken to hospital by the London Ambulance Service where he remained for a time in a critical condition. He sadly died from his injuries on Tuesday, 8 June.
His next of kin are aware and are being supported by specialist officers.
Detective Chief Inspector Kate Kieran, who is leading the investigation, said: “The victim in this case suffered the injuries that would ultimately claim his life in broad daylight, outside a residential address.
“These arrests mark significant progress in the investigation and I hope it reassures the community that officers are working hard to bring justice to the victim and his family.
“This is now a homicide investigation. I am still keen to hear from anyone who witnessed the incident or who may have dash cam footage of the stabbing itself or the events surrounding it. If you can help please don’t hesitate, call us direct or remain anonymous, but either way please do make the call.”
Any witnesses or anyone with any information should call police on 101 or Tweet @MetCC quoting CAD 5308/02JUN.
To remain 100% anonymous contact Crimestoppers on 0800 555 111 or online at crimestoppers-uk.org.
+ Hard calls save lives. Are you close to someone on the fringes of knife crime? Do the right thing, please give information, 100 per cent anonymously, through the independent charity Crimestoppers.
No piece of information about knife crime is insignificant or too small. Any information you give to Crimestoppers can make a difference in reducing knife crime and the harm it causes to families.