An agitated man was seen being taken into police custody. He was screaming obscenities at police officers from the back of the police car.
A police spokesperson confirmed officers had attended a "grievous assault". One man was arrested, and they weren't seeking anyone else in relation to the incident.
A St John spokesman said a man was taken to Wellington Hospital in serious condition. He is now being treated for moderate injuries.
Gordon Mygind, who lives down the street from incident, said he looked out his window to see a heavy police presence and a blood-soaked towel on the lawn.
He said it "scared the wits" out of him, but it wasn't the first such incident he'd come home to.