Police are examining security camera footage to help them find the assailant who knocked out an Auckland man yesterday morning.
The 36-year-old, who suffered serious head injuries when he was felled by a single punch, remains in a critical but stable condition in Auckland Hospital.
Detective Inspector Uraia Vakaruru said the man and his friend were challenged to a fight by a group of up to five men in their late teens and early 20s outside a Denny's restaurant in Manukau.
He said closed-circuit television footage from neighbouring businesses would be assessed.