"This included a very slight-looking young lady who steps out of the restaurant and right into the path of the offenders to protect the victim, who by that stage was lying unconscious on the ground," the post said.
"Several other people, including McDonald's staff, got involved and prevented any further attack."
Johnston said the man's injuries could have been a lot worse if it hadn't been for the intervention of the bystanders.
"It appeared that the offenders got a bit of a fright when they realised just how many people were there and willing to stop them. They took off pretty quick."
Two Kerikeri locals, aged 16 and 19, have been arrested and charged with wounding with intent to cause grievous bodily harm.
The post appealed for any information from the public that could help police find the people who helped the victim.