A guard working at the Herald, which is across the road from the bar, ran to help the victim. He said he tried to protect the injured man's head as the group continued to kick him.
The guard, who was left covered in blood, said he thought the victim was going to be "beaten to death" so he "had to jump in".
While police were attending the incident a second assault was reported at the Desi Lounge on Karangahape Rd, less than 2km away.
Auckland central area commander Inspector Andrew Coster said police were called to the bar at 4.30am after a group of men beat a 21-year-old, who suffered serious cuts to his neck.
"In both cases, I would suspect that if prompt medical treatment hadn't been available, we might have been looking at a very different outcome."
The 23-year-old victim remained last night in Auckland City Hospital, where doctors have him in an induced coma to help him recover from serious head injuries.
Other cases were stretching police, Mr Coster said.
"We've had a whole string of sexual and serious assaults through the Christmas period. They generally occur after 3am, at which time people in the central city have been drinking for many hours. Inevitably, the result is the carnage we have seen over recent weeks.
"This continues to confirm our view that nothing good happens in the central city after 3am."
Last year police, with the council, launched a major crackdown on drunkenness in the Auckland CBD.
Police have targeted high-risk areas and are arresting more people for breaching liquor bans.
Mr Coster said that would continue into 2013 and police would push harder to cut booze crime in the city.
"We continue to question the value of allowing alcohol to be served throughout the central city after 3am."
Boozy parties keep Waitemata police busy
Police in the Waitemata District, covering the North Shore and West Auckland, were kept busy over the weekend by alcohol-fuelled crime - including an assault where barbecue food was used as a weapon.
While Christmas and New Year are often quieter for police out in the suburbs, the hot weather and excessive drinking provided a catalyst for a lot of boozy behaviour, which resulted in 117 arrests between Friday and Sunday.
Two North Shore men had to be pepper-sprayed by police after an alcohol-fuelled altercation on Saturday night. Acting District Commander Inspector Les Paterson told the Herald that the men spent the night drinking before wandering over to a neighbour's house.
The neighbour was cooking a late-night barbecue and a fight broke out when the two men started helping themselves to meat on the grill.
"An altercation occurred and the neighbour was struck in the eye with a pork chop thrown at him by one of the men," Mr Paterson said.
"Police arrived and had to use pepper spray to subdue the pair. They spent the rest of the weekend in custody. The neighbour has not made a complaint at this stage and it's not believed he was injured."
The men will appear in the North Shore District Court facing charges including disorderly behaviour and breaching bail.
Can you help?
If you witnessed either the Desi or Jet Bar attacks, contact Detective Constable Nathan Bland at the Auckland central station on (09) 302-6737.
