He was then taken by helicopter to Dunedin Hospital.
An hour later, at 3.26am, an ambulance was called to a St Georges Ave address, on Queenstown Hill between Highview Tce and Goldfield Heights.
Another male, also with stab wounds, was found there in a serious condition.
Police believed he was injured during the earlier confrontation.
He, too, was taken by ambulance to Lakes District Hospital before being flown to Dunedin.
Det Snr Sgt Inglis said police were still looking for a knife, which may be in the Queenstown CBD.
Anyone who located it was asked to call 111 immediately.
"There were a considerable number of people and vehicles passing through the area at the time.
"Police would like to hear from anyone who either witnessed or was involved in this incident."
One Queenstown resident told the Otago Daily Times he believed the fight happened on the Village Green, opposite McDonald's.
A cordon was erected while a scene examination was carried out, but it had been removed by 8.30am.
Police would be reviewing footage from CCTV cameras in the area.