The incident happened in Maple Close near Oakleigh Way at around 7.30pm yesterday (April 28).
Officers and London Ambulance Service crews attended and found a man who had been stabbed.
He was taken to hospital for treatment where he later died.
His next of kin have been informed and police said they are awaiting formal identification.
A 24-year-old man has been arrested on suspicion of murder, officers said.
He was taken into custody after attending a south London police station on Tuesday afternoon.
Police said patrols are being stepped up in the area to provide reassurance to residents after the incident.
Detective Chief Inspector Alison Foxwell, from specialist crime south, said: “The victim’s loved ones are being supported by specially trained officers. They have our deepest sympathies following this terrible loss.
“Anybody who witnessed the incident – or who has information – should contact the police on 101, quoting CAD reference 6812/28APR.
“To remain 100% anonymous, contact Crimestoppers on 0800 555111.”
Pastor El Safo, 50, who lives nearby, told the PA news agency: “It’s a very quiet area. I’ve lived here for more than 15 years and have never seen anything like this. It’s really unfortunate and has caused a lot of panic.”
