A man has been seriously injured after being punched and falling to the ground in central Christchurch early this morning.

Emergency services were called to Hereford Street near Oxford Terrace just after 1.20AM.

A St John spokesperson said crews responded with an ambulance, rapid response unit and a manager.

They assessed and treated one patient who was transported to Christchurch Hospital in a serious condition.

Chris Lynch Media understands the man was unconscious when emergency services arrived.

A police spokesman told chrislynchmedia.com a 26 year old woman is due to appear in the Christchurch District Court on Monday facing assault charges.