Police in Auckland are investigating an assault at a junior football tournament last weekend.
Officers were alerted at about 11.30am to reports someone had been assaulted in Keith Hay Park in the suburb of Mt Roskill on Sunday.
Hato Hone St John said it was notified of the incident at 12.50pm and treated one patient in a moderate condition.
The victim was taken to hospital for checks before being discharged.
Auckland United Football Club confirmed they were aware of an incident after a game involving two non-club members.
Director of Football Ben Bate said they maintained a zero tolerance policy against poor sideline behaviour and were deeply disappointed by the assault.
"Auckland United prides itself in creating a safe and supportive environment for all, and incidents of this nature have no place in sport."
He said they wished the victim a speedy recovery.
Police said they were making enquiries to find out who was responsible for the attack.
They encouraged anyone with information to get in contact and use the reference number 241002/3521.