Police believe they are looking for a group of three to five men of Pacific origin, aged either in their late teens to early 20's.
However, police appear to have very few leads and are turning to the public for help.
Despite the Denny's restaurant where the attack took place clearly having a CCTV camera mounted on the front of the building near the entrance, police say they haven't been able to "recover" the footage yet.
"At this stage we don't have any footage, we're still canvassing the surrounding businesses and once we do come across CCTV footage we'll release it," Detective Inspector Uraia Vakaruru said.
"We believe it was working, we're still working on recovering some of that footage.
"At this stage we have very vague descriptions, we believe we are looking for three to five Pacific Island men. The descriptions are very generic."
While there were people inside the restaurant when the incident took place, it appears the only identification has come from the victim's friend - and both had been drinking alcohol prior to the incident.
"The victim's friends has indicated that his fiend has possibly suffered a punch and he's ended up on the ground," Detective Inspector Vakaruru said. "We're unsure as to what has then occurred because of the fact a few people have come out often restaurant and the men have fled in the direction of the Manukau City shopping centre."
"We're really seeking the assistance of members of the public who were in this area around 3-4am this morning. If they've seen the fight or they know the individuals involved, we would like them to ring Counties Manukau crime squad.
"We are also appealing to the three to five Pacific men as well, to come forward and help with our inquiries into the matter.
"The investigation will continue over the next day or two with further forensic scene examination. And, we will continue with the recovery and viewing of CCTV footage, and from around the surrounding businesses and also looking to talk to witnesses to come forward in the next few days."
Anyone with information can contact the Counties Manukau crime squad on 09 261 1321 or Crimestoppers on 0800 555 111.