Police were called to Enfield Playing Fields on Thursday (November 6) at 7.06pm to reports of the attack.
The victim, 18, was found at the scene with a “significant stab wound” to his leg.
He was treated by paramedics before he was taken to hospital, where his condition was found to be not life-changing or life-threatening.
The Metropolitan Police says that the victim was also robbed, but has not specified what was stolen.
It is understood by the Enfield Independent that this allegedly involved a phone and bike.
Investigations are ongoing, but no arrests have been made at this stage.
A Met Police spokesperson said: “At 19:06hrs on Thursday, 6 November officers and the London Ambulance Service responded to reports of a stabbing and robbery in Enfield Playing Fields EN1.
“One victim, a man aged 18, was met at the scene. He had a significant stab wound to the leg and after being treated by paramedics was quickly taken to hospital. His condition has not been deemed life-changing or life-threatening.
“At this stage no arrests have been made. Enquiries are ongoing. “
Anyone who witnessed the incident or has information is asked to contact police on 101 quoting ref CAD 7205/06NOV.
Alternatively, you can contact Crimestoppers anonymously on 0800 555 111.
