The incident between two men happened in Woodville Road just before 5.15pm yesterday (June 27).
Officers and London Ambulance Service crews attended and found a man, 23, injured.
He was taken to hospital for further treatment.
An update today (June 28) confirms that his injuries are not life-threatening.
No arrests have been made as police enquiries continue.
A spokesperson for the Metropolitan Police said: “Injuries are not life threatening.
“Police were called at 5.16pm on Tuesday, 27 June to reports of a fight involving two men on Woodville Road, Thornton.
“Officers responded with LAS. A 23-year-old man was found suffering stab injuries.
“He was taken to hospital for treatment.
“His condition was assessed as life changing but not believed to be life-threatening.
“No arrests at this time; enquiries are ongoing.”
