Police say a Christchurch motrocyslist they were chasing crashed while travelling speeds of up to 150km/h.
Police say they pursued the 24-year-old for about 1km on State Highway 1, south of Milton, when he failed to stop about 3pm on Friday.
They say the man crashed into a ditch and was flown to Dunedin Hospital with moderate chest injuries.
He is likely to face charges of dangerous driving and failing to stop.