Police were called to Monks Park by the London Ambulance Service shortly after 7pm following reports of a man found unresponsive.
On arrival they found the victim had suffered serious head injuries, and he was pronounced dead at the scene.
It comes only two days after a fatal shooting in the same area: a man in his 30s was gunned down in Harrow Road in Wembley on Friday night.
No arrests have been made over either death. A crime scene remains in place, and Scotland Yard’s Homicide and Major Crime Command has been informed.
Earlier on Sunday, Metropolitan Police attempted to reassure communities that extra patrols would be taking place near the scene of the Wembley shooting and in Leyton, east London, where a second fatal shooting of the weekend took place.
Police were called to the Phoenix snooker club in Lea Bridge Road just before 3am on Sunday after a man in his 20s was gunned down. Two men have been arrested on suspicion of murder over the incident.
A murder investigation is also taking place following the discovery of a woman’s body in Blackheath, south-east London, on Friday evening.
The woman has not yet been identified but the family of a woman reported missing in May have been informed. No arrests have been made.
Commenting on the latest death, Inspector Sammi Elsituri said: “This incident will no doubt alarm and shock those in the local community especially coming so soon after a fatal shooting in Wembley on Friday night.
“My officers are busy at the crime scene and will be knocking on doors and reviewing local CCTV footage to help build a clearer picture of what has taken place.
“Specialist police resources are in the area working to help solve this crime and provide reassurance to the public. Officers will be on hand to speak to locals about concerns they have.
He added: “We will work relentlessly – day and night – to identify and pursue the culprits, bring them to justice, and take weapons off the streets to keep our communities safe.”
Anyone with information on Sunday night’s incident can call police on 101 quoting CAD 6884/7 July. Anyone with information about the Wembley shooting on Friday can call 101 quoting CAD 9128/5 July.
Alternatively, you can call independent charity Crimestoppers anonymously on 0800 555 111.