The 37-year-old was attacked in Weir Road at around 7.35pm on Saturday.
The Met Police is understood to be seeking a male suspect who was chased away by members of the public.
The area’s MP, Bell Ribeiro-Addy has released this statement on X.
“Residents will be understandably distressed by this weekend’s stabbing in Balham, which has left a man in critical condition.
Full credit to the brave individuals who chased the armed attacker away.”
