Scotland Yard said the man attacked three police officers and hurled racist abuse at others as he was taken into custody.
The first officer was punched by the 32-year-old suspect after being called to a “disturbance” reportedly inside the Job Centre on High Road, Tottenham.
The officer collapsed and his colleague had to perform emergency first aid at the scene as the suspect fled at 12.30pm on Thursday.
Others chased after him and he was detained nearby, the Met said.
The officer is in a stable condition and receiving treatment in hospital.
Chief Inspector Karl Curran said: “Police officers go to work every day with the primary aim of protecting the public.
“Today, several officers have been injured by a man who had been acting aggressively towards members of the public.
“One of these officers remains in hospital. Our thoughts are we with him and his family, as well as his colleagues.
“I would like to praise the actions of the officers who quickly went to his assistance and provided him with first aid.”